Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
TRI-ARYL ETHANE DERIVATIVES AS PDE IV INHIBITORS
BACKGROUND OF THE INVENTION
This invention relates to compounds and pharmaceutical
compositions for the treatment of diseases by raising the level of cyclic
adenosine-3',5'-monophosphate (CAMP) through the inhibition of
phosphodiesterase IV (PDE IV).
Many hormones and neurotransmitters modulate tissue
function by elevating infra-cellular levels of 3', 5'-cyclic adenosine
monophosphate {cAMP). The cellular levels of cAMP are regulated by
mechanisms which control synthesis and breakdown. The synthesis of
cAMP is controlled by adenyi cyclase which may be directly activated
by agents such as forskolin or indirectly activated by the binding of
specific agonists to cell surface receptors which are coupled to adenyl
cyclase. The breakdown of cAMP is controlled by a family of
phosphodiesterase (PDE) isoenzymes, which also control the breakdown
of guanosine 3',5'-cyclic monophosphate (cGMP). To date, seven
members of the family have been described (PDE I-VII) the distribution
of which varies from tissue to tissue. This suggests that specific
inhibitors of PDE isoenzymes could achieve differential elevation of
CAMP in different tissues, [for reviews of PDE distribution, structure,
function and regulation, see Beavo & Reifsnyder (1990) TIPS, 1 l: 150-
155 and Nicholson et al (1991) TIPS, 12: 19-27].
The availability of PDE isotype selective inhibitors has
enabled the role of PDEs in a variety of cell types to be investigated. In
particular it has been established that PDE IV controls the breakdown of
CAMP in many inflammatory cells, fox example, basophils (Peachell
P.T. et al., (1992) J. Immunol. 148 2503-2510) and eosinophils (Dent
G. et al., ( 1991 ) Br. J. Pharmacol. 103 1339-1346) and that inhibition
of this isotype is associated with the inhibition of cell activation.
Furthermore, elevation of cAMP in airway smooth muscle has a
spasmolytic effect. Consequently PDE IV inhibitors are currently being
developed as potential anti-inflammatory drugs particularly for the
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prophylaxis and treatment of asthma, by achieving both anti-
inflammatory and bronchodilator effects.
The application of molecular cloning to the study of PDEs
has revealed that for each isotype there may be one or more isoforms.
For PDE IV, it is has been shown that there are four isoforms (A, B, C
and D) each coded for by a separate gene in both rodents {Swinnen J.V.
et al., (1989) Proc. Natl. Acad. Sci. LISA 86 5325-5329) and man
(Bolger G. et al., (1993) Mol. Cell Biol. 13 6558-657i).
The existence of multiple PDE IVs raises the prospect of
obtaining inhibitors that are selective for individual isoforms, thus
increasing the specificity of action of such inhibitors. This assumes that
the different PDE IV isoforms are functionally distinct. Indirect
evidence in support of this comes from the selective distribution of these
isoforms in different tissues (Swinnen et al., 1989; Bolger et al., 1993;
Obernolte R. et al., (1993) Gene 129 239-247, ibid) and the high degree
of sequence conservation amongst isoforms of different species.
To date full length cDNAs for human PDE IVA, B and D
(Bolger et al., 1993 ibid; Obernolte et al., 1993 ibid; Mclaughlin M. et
al., ( 1993) J. Biol. Chem. 268 6470-6476) and rat PDE IVA, B and D
(Davis R. et al., (1989) Proc. Natl. Acad. Sci. LISA 86 3604-3608;
Swinnen J.V. et al., (1991) J. Biol. Chem. 266 18370-18377), have been
reported, enabling functional recombinant enzymes to be produced by
expression of the cDNAs in an appropriate host cell. These cDNAs have
been isolated by conventional hybridisation methods. However using
this approach, only partial cDNAs for both human and rat PDE IVC
have been obtained. (Bolger et al., ibid. 1993 and Swinnen et al., ibid.
1989 and international Patent Specification No. WO 91/16457.)
The design of PDE IV inhibitors for the treatment of
inflammatory diseases such as asthma, has met with limited success to
date. Many of the PDE IV inhibitors which have been synthesised have
lacked potency and/or inhibit more than one type of PDE isoenzyme in a
non-selective manner. PDE IV inhibitors that are relatively potent and
selective for PDE IV, are reported to be emetic as well. Indeed this side
effect has been so universal that experts have expressed their belief that
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the emesis experienced upon administration of a PDE IV inhibitor, may
be mechanism based.
We have now found a novel series of tri-substituted phenyl
derivatives, members of which compared to known structurally similar
S compounds are potent inhibitors of PDE IV at concentrations at which
they have little or no inhibitory action on other PDE isoenzymes. These
compounds inhibit the human recombinant PDE IV enzyme and also
elevate cAMP in isolated leukocytes. Certain compounds prevent
inflammation in the lungs induced by carrageenan, platelet-activating
factor (PAF), interleukin-5 (IL-5) or antigen challenge. These
compounds also suppress the hyperresponsiveness of airway smooth
muscle seen in inflamed lungs. Advantageously, compounds according
to the invention have good oral activity and at orally effective doses
exhibit little or none of the side-effects associated with known PDE IV
inhibitors, such as rolipram. The compounds of the invention are
therefore of use in medicine, especially in the prophylaxis and treatment
of asthma and other inflammatory conditions.
SUMMARY OF THE INVENTION
The invention encompasses novel compounds of Formula I
useful in the treatment of disease by inhibition of PDE IV, resulting in
an elevation of cAMP.
0R2
R30
HEf
R =~ 1
I
The invention also encompasses certain pharmaceutical
compositions and methods for treatment of diseases by inhibition of
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PDE IV, resulting in an elevation of CAMP, comprising the use of '
compounds of Formula I.
_L?ETAILED DESCRIPTION OF THE INVENTION
The invention encompasses the novel compound of Formula
I useful in the treatment of disease by inhibition of PDE 1:V, resulting in
an elevation of cAMP,
OR2
R30
HEf
1
R
I
or a pharmaceutically acceptable salt thereof wherein:
R is selected from
(a) hydrogen,
(b) C1-6alkyl,
(c) halo and
(d) CF3
R 1 is selected from
-(CH2)m-CO-N(R4)-S(O)2-R5~ wherein m is 0, 1 or 2,
-(CH2)m-CO-N(R4)-S (O)2-NR6R~
-(CH2)m-S (O)2-N(R4)-CO-R4~
-(CH2)m-S (O)2-N(R4)-CO-NR6R~
-C{OH)(C 1 _611aloall~yl)2~ .
R2 and R3 are independently selected from
(a) C1-alkyl,
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~ (b) substituted C1-7 alkyl, wherein the substituent is F, Cl,
Br or I,
{c) 2-phenethyl or 2-indanyl, optionally mono or di-
substituted, wherein the substituents on the benzene ring are
independently selected from the group consisting of
( I ) halo,
{2) C1-6alkoxy,
(3) CI-6alkylthio,
{4) CN,
(5) CF3,
{6) C I _6alkYl,
{~) N3~
(8) -C02H,
R4 is selected from
(a) hydrogen,
(b) CI-6alkyl,
(c) phenyl, benzyl or 2-phenethyl, optionally mono or di-
substituted, wherein the substituents on the benzene ring are
independently selected from the group consisting of
( 1 ) halo,
(2) CI-6alkoxy,
{3) CI-6alkylthio,
(4) CN,
{5) CF3,
(6) CI-Salkyl,
(~) N3~
(8) -CO~i,
R5, R8 and RI 1 are each independently selected from
(a) -CF3,
(b) C 1-6alkyl,
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(c) phenyl, benzyl or 2-phenethyl, optionally mono or di-
substituted, wherein the substituents on the benzene ring are
independently selected from the group consisting of
( 1 ) halo,
(2) C1-6alkoxy,
(3) C1-6~Ylthio,
(4) CN,
(5) CF3,
(6) C 1 _6a1kY1,
(7) N3~
(8) -CO~-i,
R6, R~, R9 and R 10 are each independently selected from
(a) hydrogen, and
(b) C1_6alkyl, or
R6 and R~ may be joined to form a saturated 5, 6 or 7 membered
heterocycle, said heterocycle containing a heteroatom which is nitrogen
and optionally containing an additional hetero atom which is an O or an
S atom or NR4 , and optionally containing a carbonyl group;
HET is selected from
pyridyl and imidazolyl, optionally mono-, or disubstituted, wherein the
substituents are independently selected from halo, C 1 _6alkyl, C 1-
6alkoxy, C 1 _6alkylthio, benzyl, 2-phenethyl, NHCORB, NR9R 10,
NHS (0)2R 11 ~ OH, CN, or CF3, and the N-oxides thereof; and
X is selected from N, NCO or CH.
Within this embodiment there is a genus of compounds
wherein
R2 is cyclopentyl, and
R3 is methyl,
Within this genus there is a class of compounds wherein
R is selected from
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(a) hydrogen,
~} C1-4~y1~
{c) halo and
(d) CF3 ;
R 1 is selected from
-(CH2)m-CO-N(R4)-S(O)2-RS~ wherein m is 0, 1 or 2,
-(CH2)m-CO-N(R4)-S(O)2-NR6R~
-(CH2)m-S{O}2-N(R4)-CO-R4>
-(CH2}m-S (O)2-N {R4}-CO-NR6R~
-C (OH) (C 1 _6haloalkyl)2
RZ is cyclopentyl,
R3 is methyl,
R4 is selected from
(a) hydrogen,
(b) C1-6alkyl,
(c) phenyl, benzyl or 2-phenethyl, optionally mono or di-
substituted, wherein the substituents on the benzene ring are
independently selected from the group consisting of
( 1 ) halo,
(2} C1-6alkoxy,
(3) C1_(alkylthio,
(4) CN,
(5) CF3,
(6) Cl_6alkYl,
(7) N3,
(8) -COZH,
R~, Rg and R 11 are each independently selected from
{a} -CF3,
~) C1-6a~Yl~
(c) phenyl, benzyl or 2-phenethyl, optionally mono or di-
substituted, wherein the substituents on the benzene ring are
independently selected from the group consisting of
( 1 ) halo,
(2) C1_6alkoxy,
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(3) C1_6alkylthio,
(4) CN,
(5) CF3,
(6) C 1 _6alkYl,
(~) N3~
(8) -CO2H,
R6, R~, R9 and R10 are each independently selected from
(a) hydrogen, and
Cb) C1-6a~Yl~ or
R6 and R~ may be joined to form a saturated 5, 6 or 7 membered
heterocycle, said heterocycle containing a heteroatom which is nitrogen
and optionally containing an additional hetero atom which is an O or an
S atom or NR4 , and optionally containing a carbonyl group;
HET is selected from
pyridyl and imidazolyl, optionally mono-, or disubstituted, wherein the
substituents are independently selected from halo, C 1 _6alkyl, C 1 _
(alkoxy, C1-(alkylthio, benzyl, 2-phenethyl, NHCORg, NR9R10,
NHS (0)2R 11 ~ OH, CN, or CF3, and the N-oxides thereof; and
X is selected from N, N--~O or CH.
Within this class there is a sub-class of compounds wherein
R is selected from
(a) hydrogen,
(b) C 1-3 alkyl,
(c) halo, and
(d) CF3 ; and i s ortho to R 1;
R 1 is selected from
-(CH2)m-CO-N(R4)-S(O)2-R5~ wherein m is 0, 1 or 2,
-(CH2)m-CO-N(R4)-S(O)2-NR6R~
-(CH2)m-S (O)2-NCR4)-CO-R4~
-(CH2)m-S (O)2-N(R4)-CO-NR6R~
-C(OH)(C 1_6haloalkyl)2~
R2 is cyclopentyl,
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R3 is methyl,
R4 is selected from
(a) hydrogen,
(b) C 1 _6alkYl,
R5, Rg and R 11 are each independently selected from
(a) -CF3,
(b) C 1 _6aikyl,
R~, R~, R9 and R10 are each independently selected from
(a) hydrogen, and
(b) C 1 _6alkyl, or
R6 and R~ may be joined to form a saturated 5, 6 or 7 membered
heterocycle, said heterocycle containing a heteroatom which is nitrogen
and optionally containing an additional hetero atom which is an O or an
S atom or NR4 , and optionally containing a carbonyl group;
HET is selected from
pyridyl, optionally mono-, or disubstituted, wherein the substituents are
independently selected from halo, C 1-6alkyl, C 1 _6alkoxy, C 1-
6alkylthio, benzyl, 2-phenethyl, NHCORg, NR9R10~ NHS(O)2R11~ OH,
CN, or CF3, and the N-oxides thereof; and
XisCH.
As appreciated by those of skill in the art, Haio is intended
to include F, Cl, Br, and I.
For purposes of this specification alkyl is defined to include
linear, branched, and cyclic structures, with C 1 _6alkyl including
including methyl, ethyl, propyl, 2-propyl, s- and t-butyl, butyl, pentyl,
hexyl, 1,1-dimethylethyl, cyclopropyl, cyclobutyl, cyclopentyl and
cyclohexyl. Similarly, C1-(alkoxy is intended to include alkoxy groups
of from 1 to 6 carbon atoms of a straight, branched, or cyclic
configuration. Examples of alkoxy groups include methoxy, ethoxy,
propoxy, isopropoxy, cyclopropyloxy, cyclohexyloxy, and the like.
Likewise, C1-6alkylthio is intended to include alkylthio groups of from
1 to 6 carbon atoms of a straight, branched or cyclic configuration.
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Examples of alkylthio groups include methylthio, propylthio,
isopropylthia, cycloheptylthio, etc. By way of illustration, the
propylthio group signifies -SCH2CH2CH3. CI-6haloalkyl means an
alkyl group in which two or more hydrogen atoms have been replaced
by halogen atoms.
Exemplifying the invention are:
(a) N { (R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzoyl }methanesulfonamide,
(b) N { (R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-
(4-pyridyl)ethyl]benzoyl }benzenesulfonamide,
{c) N { (R)-4-[ I-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzoyl } trifluoromethanesulfonamide,
{d) N { (R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-
(4-pyridyl)ethyl]benzoyl } o-toluenesulfonamide,
(e) N { (R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]phenylacetyl }benzenesulfonamide,
{f) N { (R)-4-[ I-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]phenylacetyl } trifluoromethanesulfonamide,
{g) (R)-4-{2-(3-Cyclopentyloxy-4-methoxyphenyl)-2-[4-
( l, l , I ,3,3,3-hexafluoro-2-hydroxypropan-2-yl)
phenyl]ethyl } pyridine, and
(h) N (o-Toluoyl)-4-[1-(3-Cyclopentyloxy-4-
methoxyphenyl)-2-{4-pyridyl)ethyl]benzenenesulfonamide.
Some of the compounds described herein contain one or
more asymmetric centers and may thus give rise to diastereomers and
optical isomers. The present invention is meant to comprehend such
possible diastereomers as well as their racemic and resolved,
enantiamerically pure forms and pharmaceutically acceptable salts
thereof.
Some of the compounds described herein contain olefanic
double bonds, and unless specified otherwise, are meant to include both
E and Z geometric isomers.
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~ In a second embodiment, the invention encompasses
pharmaceutical compositions for treatment of disease by inhibition of
PDE IV, as disclosed herein comprising a pharmaceutically acceptable
carrier and a non-toxic therapeutically effective amount of compound of
formula I as described above.
Within this embodiment the invention encompasses
pharmaceutical compositions for treatment of disease by inhibition of
PDE IV, resulting in an elevation of cAMP, as disclosed herein
comprising a pharmaceutically acceptable carrier and a non-toxic
therapeutically effective amount of compound of formula I as described
above.
For purposes of this specification a compound is said to
selectively inhibit PDE IV in preference to other PDE's if the ratio of
the IC50 concentration for alI other PDE inhibition to PDE IV
inhibition is 100 or greater.
The pharmaceutical compositions of the present invention
comprise a compound of Formula I as an active ingredient or a
pharmaceutically acceptable salt, thereof, and may also contain a
pharmaceutically acceptable Garner and optionally other therapeutic
ingredients. The term "pharmaceutically acceptable salts" refers to salts
prepared from pharmaceutically acceptable non-toxic bases including
inorganic bases and organic bases. Salts derived from inorganic bases
include aluminum, ammonium, calcium, copper, ferric, ferrous,
lithium, magnesium, manganic salts, manganous, potassium, sodium,
zinc, and the like. Particularly preferred are the ammonium, calcium,
magnesium, potassium, and sodium salts. Salts derived from
pharmaceutically acceptable organic non-toxic bases include salts of
primary, secondary, and tertiary amines, substituted amines including
naturally occurring substituted amines, cyclic amines, and basic ion
exchange resins, such as arginine, betaine, caffeine, choline, N,N-
dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-
dimethylaminoethanol, ethanolamine, ethylenediamine, N-
ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine,
hydrabamine, isopropylamine, lysine, methylglucamine, morpholine,
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piperazine, piperidine, polyamine resins, procaine, purines,
theobromine, triethylamine, trimethylamine, tripropylamine,
tromethamine, and the like.
It will be understood that in the discussion of methods of
treatment which follows, references to the compounds of Formula I are
meant to also include the pharmaceutically acceptable salts.
Compounds according to the invention are selective and potent
inhibitors of PDE IV. The ability of the compounds to act in this way
may be simply determined by the tests described in the Examples
hereinafter.
The compounds according to the invention are thus of
particular use in the prophylaxis and treatment of human diseases where
an unwanted inflammatory response or muscular spasm (for example
bladder or alimentary smooth muscle spasm) is present and where the
elevation of cAMP levels may be expected to prevent or alleviate the
inflammation and relax muscle.
Particular uses to which the compounds of the invention
may be put include the prophylaxis and treatment of asthma, especially
inflamed lung associated with asthma, cystic fibrosis, or in the treatment
of inflammatory airway disease, chronic bronchitis, eosinophilic
granuloma, psoriasis and other benign and malignant proliferative skin
diseases, endotoxic shock, septic shock, ulcerative colitis, Crohn's
disease, reperfusion injury of the myocardium and brain, inflammatory
arthritis, chronic glomerulonephritis, atopic dermatitis, urticaria, adult
respiratory distress syndrome, diabetes insipidus, allergic rhinitis,
allergic conjunctivitis, vernal conjunctivitis, arterial restenosis and
artherosclerosis.
Compounds of the invention also suppress neurogenic
inflammation through elevation of cAMP in sensory neurones. They
are, therefore, analgesic, anti-tussive and anti-hyperalgesic in
inflammatory diseases associated with irritation and pain.
Compounds according to the invention may also elevate cAMP in
lymphocytes and thereby suppress unwanted lymphocyte activation in
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immune-based diseases such as rheumatoid arthritis, ankylosing
spondylitis, transplant rejection and graft versus host disease.
Compounds according to the invention have also been found
to reduce gastric acid secretion and therefore can be used to treat
conditions associated with hypersecretion of gastric acid.
Compounds of the invention suppress cytokine synthesis by
inflammatory cells in response to immune or infectious stimulation.
They are, therefore, useful in the treatment of bacterial, fungal or viral
induced sepsis and septic shock in which cytokines such as tumour
IO necrosis factor {TNF) are key mediators. Also compounds of the
invention suppress inflammation and pyrexia due to cytokines and are,
therefore, useful in the treatment of inflammation and cytokine-
mediated chronic tissue degeneration which occurs in diseases such as
rheumatoid or osteo-arthritis.
1 S Over-production of cytokines such as TNF in bacterial,
fungal or viral infections or in diseases such as cancer, Ieads to cachexia
and muscle wasting. Compounds of the invention ameliorate these
symptoms with a consequent enhancement of quality of life.
Compounds of the invention also elevate cAMP in certain
20 areas of the brain and thereby counteract depression and memory
impairment.
Compounds of the invention suppress cell proliferation in
certain tumour cells and can be used, therefore, to prevent tumour
growth and invasion of normal tissues.
25 For the prophylaxis or treatment of disease the compounds
according to the invention may be administered as pharmaceutical
COmpOS1t1011S, and accordi_n_g t0 a ft_lr~~'1_er acpPCtnf the invention ~xy
provide a pharmaceutical composition which comprises a compound of
formula ( 1 ) together with one or more pharmaceutically acceptable
30 carriers, excipients or diluents.
For the treatment of any of these, compounds of formula I
may be administered orally, topically, parenterally, by inhalation spray
or rectally in dosage unit formulations containing conventional non-
toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The
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term parenteral as used herein includes subcutaneous injections,
intravenous, intramuscular, intrasternal injection or infusion techniques.
In addition to the treatment of warm-blooded animals such as mice, rats,
horses, cattle sheep, dogs, cats, etc., the compound of the invention is
effective in the treatment of humans.
The pharmaceutical compositions containing the active
ingredient may be in a form suitable for oral use, for example, as
tablets, troches, lozenges, aqueous or oily suspensions, dispersible
powders or granules, emulsions, hard or soft capsules, or syrups or
elixirs. Compositions intended for oral use may be prepared according
to any method known to the art for the manufacture of pharmaceutical
compositions and such compositions may contain one or more agents
selected from the group consisting of sweetening agents, flavoring
agents, coloring agents and preserving agents in order to provide
pharmaceutically elegant and palatable preparations. Tablets contain the
active ingredient in admixture with non-toxic pharmaceutically
acceptable excipients which are suitable for the manufacture of tablets.
These excipients may be for example, inert diluents, such as calcium
carbonate, sodium carbonate, lactose, calcium phosphate or sodium
phosphate; granulating and disintegrating agents, for example, corn
starch, or alginic acid; binding agents, for example starch, gelatin or
acacia, and lubricating agents, for example, magnesium stearate, stearic
acid or talc. The tablets may be uncoated or they may be coated by
known techniques to delay disintegration and absorption in the
gastrointestinal tract and thereby provide a sustained action over a
longer period. For example, a time delay material such as glyceryl
monostearate or glyceryl distearate may be employed. They may also
be coated by the technique described in the U.S. Patent 4,256,108;
4,166,452; and 4,265,874 to form osmotic therapeutic tablets for
control release.
Formulations for oral use may also be presented as hard
gelatin capsules wherein the active ingredient is mixed with an inert
solid diluent, for example, calcium carbonate, calcium phosphate or
kaolin, or as soft gelatin capsules wherein the active ingredients is mixed
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with water or an oil medium, for example peanut oil, liquid paraffin, or
olive oil.
Aqueous suspensions contain the active material in
admixture with excipients suitable for the manufacture of aqueous
suspensions. Such excipients are suspending agents, for example sodium
carboxymethyl-cellulose, methylcellulose, hydroxy-
propylmethycellulose, sodium alginate, polyvinyl-pyrrolidone, gum
tragacanth and gum acacia; dispersing or wetting agents may be a
naturally-occurring phosphatide, for example lecithin, or condensation
products of an alkylene oxide with fatty acids, for example
polyoxyethylene stearate, or condensation products of ethylene oxide
with long chain aliphatic alcohols, for example heptadecaethylene-
oxycetanol, or condensation products of ethylene oxide with partial
esters derived from fatty acids and a hexitol such as polyoxyethylene
sorbitol monooleate, or condensation products of ethylene oxide with
partial esters derived from fatty acids and hexitol anhydrides, for
example polyethylene sorbitan monooleate. The aqueous suspensions
may also contain one or more preservatives, for example ethyl, or n-
propyl, p-hydroxybenzoate, one or more coloring agents, one or more
flavoring agents, and one or more sweetening agents, such as sucrose,
saccharin or aspartame.
Oily suspensions may be formulated by suspending the
active ingredient in a vegetable oil, for example arachis oil, olive oil,
sesame oil or coconut oil, or in mineral oil such as liquid paraffin. The
oily suspensions may contain a thickening agent, for example beeswax,
hard paraffin or cetyl alcohol. Sweetening agents such as those set forth
above, and flavoring agents may be added to provide a palatable oral
preparation. These compositions may be preserved by the addition of
an anti-oxidant such as ascorbic acid.
Dispersible powders and granules suitable for preparation
of an aqueous suspension by the addition of water provide the active
ingredient in admixture with a dispersing or wetting agent, suspending
agent and one or more preservatives. Suitable dispersing or wetting
agents and suspending agents are exemplified by those already
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mentioned above. Additional excipients, far example sweetening,
flavoring and coloring agents, may also be present.
The pharmaceutical compositions of the invention may also
be in the form of an oil-in-water emulsions. The oily phase may be a
vegetable oil, for example olive oil or arachis oil, or a mineral oil, for
example liquid paraffin or mixtures of these. Suitable emulsifying
agents may be naturally-occurring phosphatides, for example soy bean,
lecithin, and esters or partial esters derived from fatty acids and hexitol
anhydrides, for example sorbitan monooleate, and condensation
products of the said partial esters with ethylene oxide, for example
polyoxyethylene sorbitan monooleate. The emulsions may also contain
sweetening and flavouring agents.
Syrups and elixirs may be formulated with sweetening
agents, for example glycerol, propylene glycol, sorbitol or sucrose.
Such formulations may also contain a demulcent, a preservative and
flavoring and coloring agents. The pharmaceutical compositions may be
in the form of a sterile injectable aqueous or oleagenous suspension.
This suspension may be formulated according to the known art using
those suitable dispersing or wetting agents and suspending agents which
have been mentioned above. The sterile injectable preparation may also
be a sterile injectable solution or suspension in a non-toxic parenterally-
acceptable diluent or solvent, for example as a solution in I,3-butane
diol. Among the acceptable vehicles and solvents that may be employed
are water, Ringer's solution and isotonic sodium chloride solution. In
addition, sterile, fixed oils are conventionally employed as a solvent or
suspending medium. For this purpose any bland fixed oil may be
employed including synthetic mono- or diglycerides. In addition, fatty
acids such as oleic acid find use in the preparation of injectables.
Compounds of formula I may also be administered in the
form of a suppositories for rectal administration of the drug. These
compositions can be prepared by mixing the drug with a suitable non-
irritating excipient which is solid at ordinary temperatures but liquid at
the rectal temperature and will therefore melt in the rectum to release
the drug. Such materials are cocoa butter and polyethylene glycols.
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For topical use, creams, ointments, jellies, solutions or
suspensions, etc., containing the compound of Formula I are employed.
(For purposes of this application, topical application shall include mouth
washes and gargles.)
Dosage levels of the order of from about 0.01 mg to about
140 mg/kg of body weight per day are useful in the treatment of the
above-indicated conditions, or alternatively about 0.5 mg to about 7 g
per patient per day. For example, inflammation may be effectively
treated by the administration of from about 0.01 to 50 mg of the
compound per kilogram of body weight per day, or alternatively about
0.5 mg to about 3.5 g per patient per day.
The amount of active ingredient that may be combined with
the carrier materials to produce a single dosage form will vary
depending upon the host treated and the particular mode of
administration. For example, a formulation intended for the oral
administration of humans may contain from 0.5 mg to 5 g of active
agent compounded with an appropriate and convenient amount of
Garner material which may vary from about 5 to about 95 percent of
the total composition. Dosage unit forms will generally contain between
from about 1 mg to about 500 mg of an active ingredient, typically 25
mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 800
mg, or 1000 mg.
It will be understood, however, that the specific dose level
for any particular patient will depend upon a variety of factors
including the age, body weight, general health, sex, diet, time of
administration, route of administration, rate of excretion, drug
combination and the severity of the particular disease undergoing
therapy.
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a s of ~$~m_thesis
The compounds of the present invention can be prepared
according to W094/14742, published on 7 July 1994, or according to
WO 95117386, published on 29 June 1995. za wi l 1 be apparent to
$ one skilled in the art that similar methodology could be
used to prepare the enantiomers or the racemates of the
illustrated compounds.
~F',~Tl,'
Carboxylic acid derivatives were prepared by the method
presented in Scheme 1. The diastereoselective addition of Grignard
reagents derived from suitable bromoaryl-1,3-dioxolanes to acylsultsm
Michael acceptor II afforded triarylpropanoylsultam intermediates.
Removal of the chiral auxiliary, subsequent decarboxylation and
aldehyde deprotection were then performed in a one-pot fashion by
successive treatment with a suitable lithium thiolate followed by a
saponification with aqueous hydroxide and then by an aqueous acidic
treatment. In this way, carboxaldehyde intermediates were obtained.
Oxidation of those by sodium chlorite gave access to carboxylic acid
intermediates 1 and 2. Acylsulfonamides were prepared by treating
acids 1 and 2 with sulfonamides in the presence of a suitable
carbodiimide and 4-dimethylaminopyridine.
The preparation of (1,1,1,3,3,3-hexafluoro-2-
hydroxypropan-2-yl)arene derivatives is shown in Scheme 2.
Monolithiation of suitable dihaloarenes followed by the addition of
hexafluoroacetone gave access to the corresponding
bis(trifluoromethyl)carbinol intermediates which were subsequently
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protected as their trimethylsilylethoxymethyl ethers. The
diastereoselective addition of Grignard reagents derived from the latter
intermediates to acylsultam Michael acceptor II afforded
triarylpropanoylsultam intermediates. Removal of the chiral auxiliary
and subsequent decarboxylation were then performed in a one-pot
fashion by successive treatment with a suitable lithium thiolate followed
by a saponification with aqueous hydroxide and then by an aqueous
acidic treatment. Deprotection of the tertiary alcohol by treatment with
tetrabutylammonium fluoride finally afforded the desired {1,1,1,3,3,3-
hexafluoro-2-hydroxypropan-2-yl)arene derivatives.
Scheme 3
Arenesulfonamide derivatives were prepared by the method
presented in Scheme 3. Condensation of a suitable arenecarboxaldehyde
with diphenyl 1-chloro-1-(heteroaryl)methanephosphonate (J. Org.
Chem., 1992, 57, 1622) afforded the corresponding diarylalkynes. Acid
catalized addition of hydrogen iodide followed by palladium catalyzed
stannylation gave access to vinyltin intermediates. These were submitted
to palladium catalyzed coupling with N,N bis-(p-methoxybenzyl)-4-
bromobenzenenesulfonamide to yield the corresponding triarylethylene
derivatives. Reduction of the double bond was performed by reaction
with sodium borohydride and nickel{II) chloride hexahydrate and the
sulfonamide moiety was subsequently deprotected by treatment with
trifluoroacetic acid to afford the benzenesulfonamide intermediates.
Reaction of these with carboxylic acids in the presence of a suitable
carbodiimide and 4-dimethylaminopyridine gave access to
acylbenzenesulfonamide derivatives.
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cheme 1
O R2 O
R 30 ~ HET B r
J m O / Mg
N R
O
2
a
O R2
R30 ~ HET
1 ) PrSH / n-BuLi
N 2) NaOH
_ O ~ 3) Hs0+
x.~ f~~
R~/\~'~
O R2
Rg0 /
i R
- H~ NaCl02
---'
x...
R~~HO
02H
1 m=0
2 m=1
OR2
R 30
R5'S02NHz / EDC / DMAP
HET
R~rr~O-N H-S02-R5
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- Scheme 2
Br Br Br
R ~~~ 1 ) n-BuLi ~ R ~~~ SEM-CI ~ R ~~~ II / M
2) cCF3)2C0 ~.~_ ,~
Br CF3 ~ O H CF ~ OSEM
CF$ 3 CF3
O R2
R30 ~ HET
1 ) PrSH / n-BuLi
2) LiOH
O ~2 3) H30+
CF3~\ OSEM
CF3
OR2 OR2
R O / . R3 O
H~ TB-~ \ I HET
R ~~ R w
CF3~CFOSEM C~ ~ O H
a CFs
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22 -
scheme 3
. 0R2 R20
R3p ~ (Ph0)2P(O)~ HET
CI R30 ~ ~ -. H~ Nal / p-TsOH
CHO t BuOK
OR2 OR2
3
R O \ I (Me3Sn)2 / Pd(Ph3P)4 R3O
i HET
HEf
I Me3Sn
Br ~
R
R ~ Pd(Ph3P)4 / LiCI NaBH4 / NiCl2~6H20
HET
S02N(PMB)2
S02N(PMB)2
R
TFA
HET ~ HEf
I(PMB)2 S02NH2
R
OR2
R4C02H/ EDC / DMAP HEt'
SOp
H.N~O
Ra
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Compounds of Schemes 4 to b were prepared as racemic mixtures, as
described below.
Scheme 4
Coupling of 3,4-dihydroxy benzaldehyde with chlorodifluoromethane in
the presence of potassium carbonate, using DMF as solvent at 85~C,
afforded 3,4-bis-(difluoromethoxy) benzaldehyde X. This was
condensed with the lithium anion of the protected 4-bromohenyl bis-
trifluoromethyl carbinol Xa from Example 7, to afford tertiary alcohol
XI which was converted to the corresponding chloride XII using thionyl
chloride in the presence of Hunig's base in toluene solution. The
chloride XII was condensed with the a-anion of ethyl 4-pyridyl acetate,
affording the intermediate ester derivative XIII, which on hydrolysis
with lithium hydroxide in a THF-methanol-water medium, followed by
acidification with aqueous ammonium chloride afforded the
decarboxylated intermediate XIV. Removal of the SEM protecting
group was effected using TBAF in THF, leading to the final compound
XV.
Scheme 5
The compound XV was oxidized with m-chloroperoxy benzoic acid to
afford the N-oxide XVI.
Scheme 6
The 3,4-dichloropyridine analog XVIII was elaborated as follows: the
chloride XII was condensed with the lithium anion of 3,4-dichloro-
picoline, generated using LDA, affording the intermediate XVII;
removal of the SEM protecting group was effected using TBAF in THF
solution, to yield the final product XVIII.
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.~neme a
_ F2HC
CHCfFy _
H ~ ~ CHO FzfiC ~ ~ CHO
K2C03
DMF, 85°C X
Br
Xa
n-BuLi
F3C ~~TMS
CF3
SOCIp
iPrpNEt
~TMS ~TMS
p~' O O~ O
:F3 F3
COOEt
.~- ( KHMDS
1) LfOH, H20
MeOH, THF
F
1 2) aq. NH4C1 '~TMS
~TMS
p F ~ HF2 ~TBAF, THF XIV
XIII
XV
- OH
~CF3
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mCPBA
d~
O
XV XVI
Scheme 6
CFi3 OCHF2 C
C "~. C! F2HC i I \ ~ N
w
CI
LDA ..." ' ~TMS
TMS
p~p~ XVII O"O
F CFa
:F3
XtJ
BAF
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Representative compounds are shown in Tables 1 to 3
Table 1
CH
R ~02' ~ ~ m
O
EX. m R 5
1 0 CH3
2 0 Ph
3 0 CF3
4 0 o-Tol
1 Ph
6 1 CF3
Table 2
CH
CFa p H
CF3
EX. 7
S
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Table 3
CH
v w
CH3 O
Ex. 8
Table 4. In Vitro Potency of
PDE IV inhibitors.
ICso (nM)
EX. GST-Met 248 PDE
IVa
1 4
2 0.5
3 1
4 0.4
i.5
s 0.s
7 0.2
8 0.7
5 Assays for Determining Biological Activity
Establishment of CHO-K1 cell lines stable exnressin~
PDE IVa enzyme
CHO-Kl cells stably expressing the prostacyclin receptor and grown
under 6418 selection as described previously (Y. Boie, et al, 3. Biol.
Chem.: 269, 12173-12178, 1994) were plated at a density of 1.75 x 106
cells/175cm2 in a T-175 flask (Gibco, Burlington, VT) containing alpha
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MEM media; 10% heat inactivated fetal bovine serum (FBS); 1 % (v/v)
penicillin/streptomycin; 25 mM Hepes, pH 7.4; and 500 ~t.g/ml G4I8
(complete media). The cells were placed in an incubator for 24 hr at
37°C and 5% CO2. The cells were then washed with warmed sterile
phosphate buffered saline (PBS) and incubated with 2N,g/ml DNA, and 9
~t.g/mI lipofectamine reagent in Opti-MEM for 7 hr. At 37°C and 5%
C02. The incubation solution was diluted 1:2 with Opti-MEM
containing 20% FBS and incubated overnight. Following the overnight
incubation, the media was replaced by complete media containing S00
~,glml hygromycin B. Colonies were identified and grown in T-175
flasks for further characterization.
Measurement of whole-cell cAMP content
CHO-K1 cells were plated at a density of I06 cells/175 cm~ containing
complete media with 500 ~t.g/ml hygromycin. The flasks were
maintained in an incubator at 37°C with 5.0% C02 for 72 hr. The
media was changed and the cells were allowed to grow overnight. The
cells were washed and dissociated from the plate with PBS containing
0.5 mM EDTA. Cellular cAMP content was measured by centrifuging
the cell suspension at 150 g x 10 min. And resuspending the cells in a
Hanks buffered salt solution at a density of 0.2 x 106 cells/ml. The cells
were preincubated at room temperature for 15 min. and then incubated
with 10 ~t.M prostaglandin I2 (PGIa) and the indicated compound for an
additional 10 min. Basal cAMP levels were determined by incubating
the cells in 0.1 % DMSO. The incubations were terminated by the
addition of HCI (0.1 N final) and the cells measured for cAMP as
described below.
Determinations of whole-cell cAMP content were performed by
incubating 100 ~,1 reconstituted rabbit anti-succinyl cAMP serum with
100 ~,l of the whole-cell reaction or known cAMP standard and 30 pmol
of Iasl-cAMP THE in a ScintiStripT'~ well (300 ~1,I final volume) at room
temperature for 18 h. Total cpm (Bo) was determined in the absence of
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sample of cAMP standard. The reaction mixture was then aspirated out
of the well, and the individual wells were counted in a Beckman LS
6000SC with the window open from 10-999 for 1 min. The data were
expressed as %B/Bo = [(standard or sample cpm - non-specific cpm) /
(Bo cpm - non-specific cpm)] x 100. Non-specific cpm were determined
by incubating only the l2sl-CAMP THE with assay buffer (50 nM
acetate; pH S.8) in the ScintiStrip~M well. AlI determinations were
performed in triplicate.
Phosphodiesterase Scintillation Proximity Assax
CHO-K1 cells were lysed by sonication for 10 secs at a power setting of
50°10 {Braunsonic Model 2000) in an ice cold solution containing SO
mM Tris, pH 7.5; 1mM EDTA; and 200 ~M (3-mercaptoethanol.
The soluble and particulate fractions of the cell were obtained by
centrifuging the sonicate for 90 min. at 100,000 x g at 4°C. PDE
activity was measured in a solution containing SO mM Tris, pH 7.5;
IOmM MgCl2; 1 mM EDTA; and 100 nM (or indicated) 3H-cAMP
(100 ~t,l final volume) in the presence of varying concentrations of
inhibitor. The reaction mixture containing enzyme was incubated
for 10 min. at 30°C in 96-well View Plates {Packard), and
terminated by the addition of 50 ~.1 Phosphodiesterase Scintillation
Proximity Assay (SPA) Beads (Amersham) containing 18 mM
ZnS04. The amount of 3H-cAMP hydrolysis was determined by
counting the plates in a Wallac 1450 ~t,Beta LSC counter.
The Elevation of cAMP in Leukoc.
The effect of compounds of the invention on intracellular cAMP
was investigated using human neutrophils or guinea pig eosinophils.
Human neutrophils were separated from peripheral blood,
incubated with dihydrocytochalasin B and the test compound for 10
min and then stimulated with FMLP. Guinea pig eosinophils were
harvested by peritoneal lavage of animals previously treated with
intra-peritoneal injections of human serum. Eosinophils were
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separated from the peritoneal exudate and incubated with
isoprenaline and test compound. With both cell types, suspensions
were centrifuged at the end of the incubation, the cell pellets were
resuspended in buffer and boiled for 10 min prior to measurement
of cAMP by specific radioimmunoassay (DuPont).
The most potent compounds according to the Examples induced a
concentration -dependent elevation of cAMP in neutrophils and/or
eosinophils at concentrations of O.lnM to l~t,M.
Suunression of Leukocyte Function
Compounds of the invention were investigated for their effects on
superoxide generation, chemotaxis and adhesion of neutrophils and
eosinophils. Isolated leukocytes were incubated with dihydrocyto-
1 S chalasin B for superoxide generation only and test compound prior
to stimulation with FMLP. The most potent compounds of the
Examples caused a concentration-dependent inhibition of
superoxide generation, chemotaxis and adhesion at concentrations
of 0.1 nM to 1 ~t,M.
Lipopolysaccharide (LPS)-induced synthesis of tumour necrosis
factor (TNF) by human peripheral blood monocytes {PBM) is
inhibited by compounds of the Examples at concentrations of
O.OlnM to 10~t.M.
relaxation of onstricted Airwa~Smooth Muscle in vitro
The effects of compounds of the invention on guinea-pig isolated
tracheal smooth muscle were investigated. Isolated tracheal rings
were suspended in organ baths and immersed in oxygenated Kxebs'
solution. The smooth muscle was contracted with sub-maximal
concentrations of histamine or carbachol prior to the addition of
increasing concentrations of test compound to the organ baths. The
most potent compounds of the Examples caused a concentration-
dependent reversal of both histamine and carbachol-induced
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contractions at concentrations of 1nM to 100~t.M. The compounds
were generally more potent in reversing histamine-induced tone
than carbachol-induced tone.
EFfects on Cardiac Muscle in vitro
Compounds of the invention have been tested for their effects on
isolated cardiac muscle. Right atrial and papillary muscles were
dissected out from the hearts of guinea pigs and suspended in organ
baths for measuring the rate {chronotropic) of spontaneously
beating atria and force (inotropic) of the electrically stimulated
papillary muscle. In these preparations, selective PDE IV
inhibitors such as rolipram do not have any direct effects whereas
selective PDE III inhibitors such as milrinone have positive
chronotropic and inotxopic effects. The non-specific PDE inhibitor
theophylline, which is used in asthma as a bronchodilator, also
causes significant cardiovascular changes such as tachycardia.
Selective PDE IV inhibitors have advantage over theophylline,
therefore, through reduced cardiovascular side effects. The most
potent and selective compounds of the Examples had no direct
effects on the atrial and papillary muscles in vitro at concentrations
up to 10~t.M but in combination with PDE III inhibitors, these
inhibitors showed an enhancement of chronotropic and inotropic
activity, typical of selective type IV inhibitors.
Anti-inflammatory Activity in vivo
Interleukin-5 (IL-5)-induced pleural eosinophilia in the rat (Lisle,
et al. 1993, Br.J. Pharmacol. 108. 230p) is inhibited by compounds
of the Examples given orally at doses of 0.0001 to lO.Omg/kg. The
most potent compounds cause a dose-dependent reduction in
migrating eosinophils with EDSOS of 0.003 to 0.03mg/kg p.o.
Compounds of the invention also reduce the inflammatory
responses induced in rats by platelet activating factor (PAF~.
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Anti-allergic Activity in vivo
Compounds of the invention have been tested for effects on an IgE-
mediated allergic pulmonary inflammation induced by inhalation of
antigen by sensitised guinea pigs. Guinea pigs were initially
S sensitised to ovalbumin under mild cyclophosphamide-induced
immunosuppression, by intraperitoneal injection of antigen in
combinations with aluminium hydroxide and pertussis vaccine.
Booster doses of antigen were given two and four weeks Iater and
at six weeks, animals were challenged with aerosolised ovalbumin
IO whilst under cover of an intraperitoneally administered anti-
histamine agent (mepyramine). After a further 48h, bronchial
alveolar lavages (BAL) were performed and the numbers of
eosinophils and other leukocytes in the BAL fluids were counted.
The lungs were also removed for histological examination for
IS inflammatory damage. Administration of compounds of the
Examples (0.001-IOmg/kg i.p. or p.o.), up to three times during
the 48h following antigen challenge, lead to a significant reduction
in the eosinophilia and the accumulation of other inflammatory
leukocytes. There was also less inflammatory damage in the lungs
20 of animals treated with compounds of the Examples.
effects on PuImonarv Dynamics
Compounds of the invention (0.001-lOmg/kg by oral or other route
of aministration) reduce the allergic bronchoconstruction caused by
25 antigen in sensitized guinea pigs.
Compounds of the invention have been tested for their effects on
ozone-induced hyperreactivity of the airways of guinea pigs.
Following the inhalation of ozone, guinea pigs become very much
30 more sensitive to the bronchoconstrictor effects of inhaled
histamine than naive animals (Yeadon et al, 1992, Pulmonary
Pharm., ~, 39). There is a pronounced shift to the Ieft (I0-30 fold)
of the dose response curve to histamine and a highly significant
increase in the maximum increase in pulmonary resistance.
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Compounds of the Examples administered 1h prior to ozone by the
intraperitoneal or oral (0.001-1 Omg/kg) route caused a dose-
dependent inhibition of ozone-induced hyperreactivity.
Adverse Effects
Compounds of the invention are free from adverse effects
following repeated overdosage to rats or dogs. For example, over
administration of 125mglkglday of active compounds of the
Examples to rats for 30 days is not associated with adverse toxicity.
The most potent compounds of the invention are 20-30 times Iess
active than rolipram in inducing behavioural changes, sedation or
emesis in rats, ferrets or dogs.
SPA based PDE activity assa~protocol
Compounds which inhibit the hydrolysis of CAMP to AMP by the
type-IV cAMP-specific phosphodiesterases were screened in 96-
well plate format as follows:
In a 96 well-plate at 30 °C was added the test compound (dissolved
in 2 u1 DMSO), 188 mI of substrate buffer containing [2,8-3H]
adenosine 3',5'-cyclic phosphate (CAMP, 100 nM to 50 ~t.M), 10
mM MgCI2, 1 mM EDTA, 50 mM Tris, pH 7.5. The reaction was
initiated by the addition of 10 ml of human recombinant PDE-IV
(the amount was controlled so that -- 10% product was formed in
10 min. at 30 °C). The reaction was stopped after 10 min. by the
addition of 1 mg of PDE-SPA beads (Amersham). The product
AMP generated was quantified on a Microbeta 96-well plate
counter. The signal in the absence of enzyme was defined as the
background. 100% activity was defined as the signal detected in the
presence of enzyme and DMSO with the background subtracted.
Percentage of inhibition was calculated accordingly. IC50 value
was approximated with a non-linear regression fit of the standard
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4-parameter/multiple binding sites equation from a ten point
titration.
IC50 values shown in Table 4 were determined with 100 nM cAMP
using the purified GST fusion protein of the human recombinant
phosphodiesterase IVa (met-248) produced from a baculovirus/Sf 9
expression system.
The invention will now be illustrated by the following non-
limiting examples in which, unless stated otherwise:
(i) all operations were carried out at room or ambient
temperature, that is, at a temperature in the range 18-25°C;
evaporation
of solvent was carried out using a rotary evaporator under reduced
1 S pressure (600-4000 pascals: 4.5-30 mm. Hg) with a bath temperature of
up to 60°C; the course of reactions was followed by thin layer
chromatography {TLC) and reaction times are given for illustration
only; melting points are uncorrected and 'd' indicates decomposition; the
melting points given are those obtained for the materials prepared as
described; polymorphism may result in isolation of materials with
different melting points in some preparations; the structure and purity
of all final products were assured by at least one of the following
techniques: TLC, mass spectrometry, nuclear magnetic resonance
(NMR) spectrometry or microanalytical data; yields are given for
illustration only; when given, NMR data is in the form of delta (~)
values for major diagnostic protons, given in parts per million (ppm)
relative to tetramethylsilane {TMS) as internal standard, determined at
300 MHz or 400 MHz using the indicated solvent; conventional
abbreviations used for signal shape are: s. singlet; d. doublet; t. triplet;
m. multiplet; br. broad; etc.: in addition "Ar" signifies an aromatic
signal; chemical symbols have their usual meanings; the following
abbreviations leave also been used v (volume), w (weight), b.p. (boiling
point), m.p. (melting point), L (Iiter(s)), mL {milliliters), g {gram(s)),
mg (milligrams(s)), mol (moles), mmol (millimoles), eq (equivalent(s)).
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' The following abbreviations
have the indicated meanings:
Ac - acetyl
Bn - benzyl
cAMP cyclic adenosine-3',5'-monophosphate
DBU - 1,8-diazabicyclo[5.4.0]undec-7-ene
DIBAL - diisobutylaluminum hydride
DMAP - 4-(dimethylamino)pyridine
DMF - N,N-dimethylformamide
Et3N - triethylamine
GST glutathione transferase
LDA - lithium diisopropylamide
m-CPBA - metachloroperbenzoic acid
MMPP - monoperoxyphtalic acid
MPPM - monoperoxyphthalic acid, magnesium salt
6H20
Ms - methanesulfonyl = mesyl = S02Me
Ms0 - methanesulfonate = mesylate
NSAID - non-steroidal anti-inflammatory drug
o-Tol - ortho-tolyl
OXONE~ = 2KHSO5KHS04K2S04
PCC - pyridinium chlorochromate
PDC - pyridinium dichromate
PDE phosphodiesterase
Ph - phenyl
Phe - benzenediyl
PMB - para-methoxybenzyl
Pye - pyridinediyl
r.t. - room temperature
rac. - racemic
SAM - aminosulfonyl or sulfonamide or
SOZNH2
SEM 2-(trimethylsilyl)ethoxymethoxy
SPA scintillation proximity assay
TBAF - tetra-n-butylammonium fluoride
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Th - 2- or 3-thienyl
TFA - trifluoroacetic acid
TFAA - trifluoroacetic acid anhydride
Z'~ - tetrahydrofuran
T~ - thiophenediyl
'1'1-C - thin layer chromatography
TMS-CN - trimethylsilyl cyanide
Tz - 1H (or 2H)-tetrazol-5-yl
C3H5 - allyl
Alkyl GroupAbbreviations
Me - methyl
Et - ethyl
n-Pr - normal propyl
i-Pr - isopropyl
n-Bu - normal butyl
i-Bu - isobutyl
s-Bu - secondary butyl
t-Bu - tertiary butyl
c-Pr - cyclopropyl
c-Bu - cyclobutyl
c-Pen - cyclopentyl
c-Hex - cyclohexyl
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EXAMPLE 1
N I (Rl-4-f 1-(3-Cyclopentvloxy-4-methoxy~henyll-2-(4-
pvrid 1~)ethvllbenzo~}methanesulfonamide
A solution of carboxylic acid intermediate 1 (100 mg, 0.24
mmol), methanesulfonamide (27 mg, 0.29 mmol), 1-(3-
dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (92 mg, 0.48
mmol) and 4-dimethylaminopyridine {35 mg, 0.29 mmol) in CH2Cl2 (3
mL) was stirred at room temperature for 19 h. Glacial acetic acid {0.2
mL) was then added and, after 10 min, CH2CI2 was added. The organic
phase was washed by 25% aqueous NH40Ac, water and brine, dried
(MgS04) and concentrated. The residue was purified by column
chromatography on silica (CH2C12/MeOH 92:8) to afford the title
compound as a white solid (63 mg, 53%). 1H NMR (400 MHz, acetone-
d6): S 1.55 {m, 2H), 1.75 {m, 6H), 2.95 (bs, 3H), 3.40 (d, 2H), 3.70 {s,
3H), 4.40 {t, 1H), 4.75 {m, 1H), 6.80 (m, 2H), 6.90 (s, 1H), 7.15 (d,
2H), 7.35 (d, 2H), 7.95 (d, 2H), 8.35 {d, 2H).
EXAMPLE 2
N ( (R)-4-f 1-(3-C~pentyloxy-4-methoxyphen 1~)-2-(4-
pYrid I~ lethYljbenzovl }benzenesulfonamide
Following the procedure described in Example 1 but
substituting benzenesulfonamide for methanesulfonamide, the title
compound was obtained as a white solid (79%). 1H NMR (400 MHz,
acetone-d6): S 1.55 (m, 2H), 1.70 (m, 6H), 3.40 (d, 2H), 3.70 (s, 3H),
4.40 (t, 1H), 4.75 (m, 1H), 6.80 (s, 2H), 6.90 (s, 1H), 7.15 (d, 2H),
7.25-7.45 (m, SH), 7.95 (m, 4H), 8.35 (d, 2H).
EXAMPLE 3
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N I tR)-4-f l-t3-Cvclopent loxv-4-methoxyphen~) 2 t4
nvridvl)ethvllbenzo~} trifluoromethanesulfonamide
Following the procedure described in Example I but
substituting trifluoromethane-sufonamide for methanesulfonamide, the
title compound was obtained as a white solid (68%). IH NMR (400
MHz, acetone-d6): 8 1.55 (m, 2H), 1.70 {m, 6H), 3.40 (d, 2H), 3.70 {s,
3H), 4.40 (t, 1 H), 4.75 {m, 1 H), 6.80 (s, 2H), 6.90 {s, 1 H), 7.15 (d, 2H),
7.35 (d, 2H), 8.00 (d, 2H), 8.35 (d, 2H).
EXAMPLE 4
lV-1tR)-4-fI-t3-Cyclopentvloxv-4-methoxyphen~) 2 t4
uvridyl)ethyllbenzo~l }o-toluenesulfonamide
Following the procedure described in Example 1 but
substituting o-toluenesufonamide for methanesulfonamide, the title
compound was obtained as a white solid {83%). IH NMR (400 MHz,
DMSO-d6): s 1.50-1.70 (m, 6H), I.80 (m, 2H), 2.55 (s, 3H), 3.40 (d,
2H), 3.65 (s, 3H), 4.40 {t, I H), 4.70 (m, I H), 6.80 (s, 2H), 6.90 {s, 1 H),
7.20 (d, 2H), 7.30-7.45 (m, 4H), 7.55 (t, 1H), 7.75 (d, 2H), 8.00 {d,
IH), 8.35 (d, 2H).
EXAMPLE 5
N ItR)-4-fl-t3-Cyclopent loxy-4-methoxynhen Ice) 2 t4
p~ridvl)eth ~~llphenylacetyllbenzenesulfonamide
Following the procedure described in Example 1 but
substituting carboxylic acid intermediate 2 for intermediate 1 and
benzenesulfonamide for methanesulfonamide, the title compound was
obtained as a white solid (43%). 1H NMR (400 MHz, acetone-d6): s
1.50-I.62 {m, 2H), 1.63-1.87 (m, 6H), 3.37 (d, 2H), 3.57 (s, 2H), 3.70
(s, 3H), 4.3I {t, J = 8 Hz, IH), 4.74 (m, IH), 6.78 (m, 2H), 6.88 (s, 1H),
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7.07 (d, J = 8 Hz, 2H), 7.13 (d, J = 6 Hz, 2H), 7.25 (d, J = 8 Hz, 2H),
7.54 (m, 2H), 7.66 (m, 1H), 7.94 (d, J = 7 Hz, 2H), 8.33 (d, J = 6 Hz,
2H).
EXAMPLE 6
.N 1 (R)-4-f 1-(3-Cvclopentvloxy-4-methoxy~henyll-2~4-
pyridvl)eth~],phen 1~~}trifluoromethanesulfonamide
Following the procedure described in Example 1 but
substituting carboxylic acid intermediate 2 for intermediate 1 and
trifluoromethanesulfonamide for methanesulfonamide, the title
compound was obtained as a white solid (80%). 1H NMR (400 MHz,
acetone-d6): 8 1.51-1.63 (m, 2H), 1.64-1.90 (m, 6H), 3.39 (m, 4H),
3.70 (s, 3H), 4.30 (t, 1H), 4.76 (m, 1H), 6.79 (m, 2H), 6.92 (s, 1H),
7.15 (m, 4H), 7.25 (d, J = 8 Hz, 2H), 8.33 (m, 2H).
EXAMPLE 7
(R)-4-12-(3-C~pentvloxv-4-methox nhenyll-2-[4-(1 1 1 3 3 3-
hexafluoro-2-hvdroxxpropan-2-ylluhen l~lethyl } pyridine
Step 1: 2-(4-Bromophenyl)-l,1,1,3,3,3-hexafluoro-2-propanol
n-Butyllithium (2.4 M solution in hexane; 92.7 mL, 0.222
mol) was added dropwise (20 min) to a solution of p-dibromobenzene
(50.0 g, 0.212 mol) in Et20 ( 1.2 L) at -60 °C. After completion of the
addition, the reaction was left at -50 °C for 30 min and
hexafluoroacetone (42.2 g, 0.254 mol) was bubbled through the
heterogeneous mixture, at the same temperature. The resulting solution
was allowed to warm to -30 °C over 30 min before saturated aqueous
NH4C1 was added. The aqueous layer was extracted with EtOAc (2x)
and the combined organic extracts were successively washed with 25 %
aqueous NH40Ac buffer, water and brine, dried (MgS04) and
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concentrated. The residue was distilled under reduced pressure (bp 85-
90 °C/12 mmHg) to afford the title compound as colorless crystals (53.5
g, 78%).
S Step 2: 2-(4-Bromophenyl)-2-[2-(trimethylsilyl)ethoxymethoxy]-
1,1,1,3,3,3-hexafluoropropane
A solution of 2-(trimethylsilyl)ethoxymethyl chloride (25.9
g, O.1SS mol) in CH2Cl2 (SO mL) was added dropwise to a solution of
2-(4-bromophenyl)-1,1,1,3,3,3-hexafluoro-2-propanol from Step 1
(38.6 g, 0.120 moI) in the same solvent (500 mL) at 0 °C. After
completion of the addition, the mixture was allowed to warm to room
temperature, and stirred for 3 h before it was diluted with CHC13 (S00
mL). The resulting solution was washed successively with 1 N HCl (2x),
1S saturated aqueous NaHC03, water and brine, dried {Na2S04) and
concentrated. The residue was distilled under reduced pressure (bp 128
°C/0.9 mmHg) to afford the title compound as a colorless liquid (50.0
g,
92%).
Step 3: (1R, SSA-N {(3R)-3-(3-Cyclopentyloxy-4-methoxyphenyl)-3-[4-
{2-(2-(trimethylsilyl)ethoxymethoxy)-1,1,1,3,3,3-hexafluoropropan-2-
yl)phenyl]-2-(4-pyridyl)propanoyl }-10,10-dimethyl-3-thia-4-
azatricyclo[5.2.1.015]decane-3,3-dioxide
2S A solution of 2-(4-bromophenyl)-2-[2-
(trimethylsilyl)ethoxymethoxy]-1,1,1,3,3,3-hexafluoropropane from
Step 2 (30.4 g, 67.1 mmol) in THF ( 1 S mL) was added to magnesium
turnings (1.71 g, 70.4 mmol) in THF (40 mL). A few crystals of iodine
were added and the mixture was stirred at reflux temperature for 1 h
before it was added dropwise to a solution of acyl sultam I~ ( 12.0 g,
22.4 mmol) in THF (200 mL) at 0 °C. The reaction mixture was stirred
at room temperature for 16 h and quenched by the addition of saturated
aqueous NH4Cl. The organic layer was concentrated and diluted with
EtOAc, and the aqueous phase extracted with EtOAc (2x). The
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combined organics were washed successively with 25% aqueous
NH40Ac buffer, water and brine, dried (MgS04) and evaporated. The
residue was recrystallized in EtOH and further purified by column
chromatography on silica (acetone/CHCl3 5:95) to afford a first crop of
S the title compound as a white solid. The EtOH filtrate was concentrated
and purified successively by column chromatography (as above) and
recrystallization (EtOH) to give a second crop for a total mass of 9.48 g
(46%).
Step 4: (R)-4-{ 2-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-(2-(2-
(trimethylsilyl)ethoxymethoxy)-1,1,1,3,3,3-hexafluoropropan-2-
yl)phenyl] ethyl } pyridine
n-Butyllithium (2.4 M solution in hexane; 7.76 mL, 18.6
mmol) was added dropwise to a solution of I-propanethiol (2.06 mL,
22.8 mmol) in THF ( 100 mL) at 0 °C. After 1.5 h, a solution of ( 1R,
5S)-N { (3R)-3-(3-cyclopentyloxy-4-methoxyphenyl)-3-(4-(2-(2-
(trimethylsilyl)ethoxymethoxy)-1,1,1,3,3,3-hexafluoropropan-2-
yl)phenyl]-2-(4-pyridyl)propanoyl }-10,10-dimethyi-3-this-4-
azatricyclo[5.2.1.01 ~5]decane-3,3-dioxide from Step 3 (9.43 g, 10.4
mmol) in THF (25 mL) was added dropwise, at 0 °C, and the reaction
mixture was stirred at room temperature for 3 h. The reaction was then
quenched by the addition of 25% aqueous NH40Ac buffer. The aqueous
layer was extracted with EtOAc (2x), and the combined organics were
washed successively with 25% aqueous NH40Ac buffer and brine, dried
(MgS04) and concentrated. The residue was dissolved in EtOH (170
mL) and water (57 mL), lithium hydroxide monohydrate (2.20 g, 52.0
mmol) was added and the mixture heated to reflux for 2.5 h. The
reaction mixture was cooled to room temperature before the addition of
AcOH (3.56 mL, 62.1 mmol). After 30 min., 25% aqueous NH40Ac
buffer was added and the aqueous layer extracted with EtOAc (2x). The
combined organics were washed successively with 25% aqueous
NH40Ac buffer and brine, dried (MgS04) and concentrated. The
residue was purified by column chromatography on silica
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(EtOAclhexane 1:1) to afford the title compound as a colorless gum
(4.08 g, 58%).
Step 5: {R)-4- { 2-(3-Cyclopentyloxy-4-methoxyphenyl)-2-[4-
(l, l,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)phenyl]ethyl }pyridine
Tetrabutylammonium fluoride ( 1.0 M in THF; 30.4 mL,
30.4 mmol) was added dropwise to a solution of {R)-4-{ 2-(3-
cyclopentyloxy-4-methoxyphenyl)-2-[4-(2-(2-
{trimethylsilyl)ethoxymethoxy)-1,1,1,3,3,3-hexafluoropropan-2-
yI)phenyl]ethyl }pyridine from Step 4 (4.08 g, 6.09 mmol) in THF (50
mL) at room temperature, and the resulting solution was heated to the
reflux temperature for 2.5 h, allowed to cool, and 25% aqueous
NH40Ac buffer was added. The aqueous layer was extracted with
I5 EtOAc (3x), and the combined organics were washed successively with
25% aqueous NH40Ac buffer, water and brine, dried (MgS04) and
concentrated. The residue was purified by column chromatography on
silica (EtOAc/hexane 1:1 ) to afford a white solid subsequently triturated
in 1:4 Et20/hexane to give the title compound (2.87 g, 87%). 1H NMR
(400 MHz, acetone-d6) 8 1.50-1.62 (m, 2H), I.63-I.88 (m, 6H), 3.44
(m, 2H), 3.71 (s, 3H), 4.43 (t, J = 8 Hz, 1H), 4.75 {m, 1H), 6.81 (m,
2H), 6.89 (s, 1H), 7. I4 (d, J = 6 Hz, 2H), 7.44 (s, IH), 7.5 i {d, J = 8 Hz,
2H), 7.67 (d, J = 8 Hz, 2H), 8.33 {d, J = 6 Hz, 2H).
EXAMPLE 8
N to-Toluovll-4-f 1-(3-Cvclopentyloxv-4-methoxvphenvl) 2 f4
pvridyl)ethyllbenzenenesulfonamide
Step I: (3-Cyclopentyloxy-4-methoxyphenyl)(4-pyridyl)acetylene
To a suspension of 3-cyclopentyloxy-4-
methoxybenzaldehyde (6.07 g, 27.6 mmol) and diphenyl 1-chloro-1-(4-
pyridyl)methanephosphonate (J. Org. Chem., 1992, 57, 1622) (9.03g,
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52.1 mmol) in dioxane (150 mL) there was added in portions potassium
tert-butoxide (7.03g, 62.8 mmol). The mixture was stirred at room
temperature for 1 h and then refluxed. After 3.5 h, there was added
another 7 g of potassium tent-butoxide and refluxing was continued for
18 h. After cooling, the mixture was diluted with water ( 1 L) and
extracted 3 times with EtOAc. The extracts were washed 3 times with
water, dried and evaporated and the residue was chromatographed on
silica gel (EtOAc/hexane 1:2} to afford the title acetylene (4.72g, 64%)
as a cream-colored solid.
Step 2: 1-(3-Cyclopentyloxy-4-methoxyphenyl)-1-iodo-2-(4-
pyridyl)ethylene
To a solution of acetylene from step 1 (8.79g, 30 mmol} in
dichloromethane {600 mL) at room temperature there was added a solid
mixture of sodium iodide ( 18g, 120 mmol) and p-toluenesulfonic acid
monohydrate (11.4 g, 60 mmol}. The mixture was stirred at room
temperature for 18 h. The mixture was diluted with aqueous 1 N NaOH
(600 mL) and stirred vigorously for 15 min. The organic phase was
collected and washed 3 times with water, dried and evaporated to a
residue which was stirred in a 2: I mixture of hexane and ether ( 100mL)
for 2 h and filtered to afford the desired vinyl iodide (8.46g, 67%) as a
beige solid, assayed by NMR to be a 4:1 mixture of Z and E isomers.
Step 3: 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-pyridyl)-1-
(trimethylstannyl)ethylene
A mixture of vinyl iodide from step 2 { I .9 g, 4.5 mmol)
and hexamethylditin (2.15g, 6.6 mmol) in toluene (25 mL) was placed
under N2 atmosphere. There was added tetrakis
(triphenylphosphine)palladium(0) ( 180 mg, 0.12 mmol) and the mixture
was heated at 90°C for 18 h. After cooling, the mixture was diluted
with
EtOAc and washed 3 times with water, dried and evaporated. The crude
product was chromatographed on silica gel (hexane/EtOAc i :1 ) to yield
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the title vinyl stannane (1.28g, 62%} as a thick syrup, assayed by NMR
to be a 10:1 mixture of Z and E isomers.
Step 4: N,N Bis-(p-methoxybenzyl}-4-~1-(3-cyclopentyloxy-4-
methoxyphenyl)-2-(4-pyridyl)ethenyl]benzenenesulfonamide
A solution of the vinyltin intermediate from Step 3 (2.03 g,
4.4 mmol), N,N bis-(p-methoxybenzyl)-4-bromobenzenenesulfonamide
{1.30 g, 2.7 mmol}, tetrakis(triphenyl-phosphine)palladium(0) (0.26 g,
0.22 mmol) and lithium chloride (0.8 g, 19 mmol) in 1,4-dioxane (15
mL} was refluxed for 5 days. EtOAc was then added and the organic
phase was washed successively with 25% aqueous NH40Ac buffer,
water and brine, dried (MgS04) and concentrated. The residue was
purified by flash-chromatography (silica gel, hexane/EtOAc 65:35 to
40:60) to afford the title compound as a yellow solid (0.81 g, 43%).
Step 5: N,N Bis-(p-methoxybenzyl)-4-[ 1-{3-cyclopentyloxy-4-
metlloxyphenyl)-2-{4-pyridyl)ethyl]benzenenesulfonamide
Sodium borohydride (80 mg, 2.I mmol) was added
portionwise to a 0°C solution of alkene from step 4 (452 mg, 0.65
mmol) and nickel(II) chloride hexahydrate (30 mg, 0.13 mmol) in
MeOH (4 mL) and THF (2 mL). The reaction mixture was stirred at
room temperature for 70 min before it was cooled to 0°C and a second
portion of nickel(II) chloride hexahydrate (75 mg, 0.32 rnmol) and
sodium borohydride (60 mg, 1.6 mmol) was added. After 18 h at room
temperature, more sodium borohydride (5 X 50 mg, 6.6 mmol) was
added on a period of 6 h to achieve complete transformation of the
starting material. The reaction mixture was then filtered over celite, the
cake was washed with MeOH and the filtrate were evaporated. The
residue was dissolved in EtOAc and the organic phase was washed
successively with 25% aqueous NH40Ac buffer, water and brine, dried
{MgS04) and concentrated. The residue was purified by flash-
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chromatography (silica gel, hexane/EtOAc 40:60 to 25:75) to afford the
title compound as a colorless gum (236 mg, 52%).
Step 6: 4-[1-(3-cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzenenesulfonamide
Trifluoroacetic acid (0.5 mL) was added to a 0°C solution
of protected sulfonamide from Step 5 (98 mg, 0.14 mmol) in Cl-I2C12 (3
mL) and the reaction mixture was stirred at room temperature for 24 h.
EtOAc was then added and the organic phase was washed successively
with 25% aqueous NH40Ac buffer, water and brine, dried (MgS04)
and concentrated. The residue was purified by flash-chromatography
(silica gel, EtOAc) to afford the title compound as an off white solid (46
mg, 72%).
Step 7: N (o-Toluoyl)-4-j1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzenenesulfonamide
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EXAMPLE 9
__4-12-(3.4-Difluoromethoxy)phenyl-2-f4-(I 1 1 3 3 3 hexafluoro 2
hvdroxyp~pan-2- 1)nhenvllethv~, ridine
a I 3.4-Bis(difluoromethoxy)benzaldehvde
A suspension of 3,4-dihydroxybenzaldehyde (6.9 g, 50
mmol) and powdered potassium carbonate { 13.8 g, 100 mmol) in N,N-
dimethylformamide. (400 mL) was cooled to -45~C.
1O Chlorodifluoromethane was bubbled into the mixture until 19 g had
been dissolved (219 mmol). A dry ice condenser was installed and the
temperature was raised gradually to 85~C, and kept at that temperature
for 16 hours. After cooling to room temperature, the mixture was
carefully diluted with water {600 mL) and extracted 4 times with ether,
the extracts were washed 3 times with brine, dried and evaporated. The
residue was chromatographed on silica gel, eluting with a 1:3 mixture of
ethyl acetate and hexane, to afford the desired product as a colorless
liquid (4.7 g, 39.5%)
1H NMR {400 MHz, acetone-d6) d 7.13 (t, large J, 1H); 7.20 (t, large J,
1H); 7.58 (d, 1H); 7.87 (s, 1H); 7.93 (d, 1H); 10.04 (s, 1H).
Step 2 T3 4-Bis(difluoromethoxv)nhenyll {4 ~2 f2 trimeth, 1~ silvl
~thoxv)methoxyl-1 1 1 ~_3 3-hexafiuoroproyan 2 y1
phenyl } methanol
To a solution of 2-(4-bromophenyl)-2-[2-(trimethylsilyl)
ethoxy methoxy]-1,1,1,3,3,3-hexafluoro propane from Example 7, Step
2 (2.44 g, 5.4 mmol) in THF ( 15 mL) at -78~C was added n-
butyllithium in hexanes { 1.25 M, 4 mL, 5 mmol), and the resulting
solution was kept at -78~C for 20 minutes. This solution was added via
canula, to a solution of 3,4-bis{difiuoromethoxy) benzaldehyde from
step I ( 1.31 g, 5.5 mmol) in THF { 10 mL). The resulting yellow
solution was stirred at -78~C for 1 hour, then quenched with sat'd aq.
ammonium chloride, allowed to warm up and partitioned between ether
and water. The crude organic product was chromatographed on silica
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gel, eluting with a 1:19 mixture of ethyl acetate and toluene, to afford
the desired secondary alcohol (1.86 g, 55%) as a colorless syrup.
1H NMR (400 MHz, acetone-d6) d 0.05 (s, 9H), 0.98 (t, 2H); 3.86 {t,
2H); 4.93 (s, 2H); 5.28 (d, 1H, OH); 5.95 (d, 1H); 6.92 {t, large J, 1H);
6.96 (t, large J, 1H); 7.30 (d, 1H); 7.36 (d, 1H); 7.50 (s, 1H), 7.64 (s,
4H).
Step 3 f3.4-Bistdifluoromethoxylphenvll~-, 4-(2-(2-trimethvlsil~
ethoxy)methoxy]-1.1.1 3 3 3-hexafluoro nropan-2~~
ghenvl } chloromethane
To a solution of secondary alcohol from Step 2 (918 mg,
1.5 mmol) and N,N-diisopropylethylamine (275 mg, 1.65 mmol) in
toluene (15 mL) was added thionyl chloride (357 mg, 3 mmol). The
mixture was stirred at room temperature for 1 hour, concentrated and
chromatographed as such on silica gel, eluting with a 1:5 mixture of
ethyl acetate and hexane, to afford the desired chloride (762 mg, 81 %)
as a colorless syrup.
1H NMR (400 MHz, acetone-d6) d 0.05 {s, 9H); 0.98 (t, 2H); 3.86 (t,
2H); 4.94 (s, 2H); 6.55 (s, 1H); 7.02 (t, large J, 2H); 7.39 (d, 1H); 7.48
{d, 1H); 7.55 (s, 1H); 7.72 {s, 4H).
to 4 4-{ 1-Carbethoxy-2-f3.4-bisfdifluoromethox )nhenyll-2-~4-
i2-f2-trimethyl~ilvl)ethoxymethoxY)-1 i 1 3 3 3-
~lexafluoropropan-2-vllphen l~leth~}pyridine
To a solution of ethyl 4-pyridyl acetate (236 mg, 1.43
mmol) and hexamethylphosphoramide (256 mg, 1.43 mmol) in THF (8
mL) at -78~C was added potassium bis(trimethylsilyl)amide 0.85 M in
THF (1.56 mL, 1.33 mmol). The resulting red-orange solution was
stirred at -78~C for 1 hour, then was added, with canula, to a cold {-
78~C) solution of chloride from Step 3 (600 mg, 0.95 mmol) in THF (8
mL). The mixture was warmed to room temperature and stirred
overnight. After quenching with sat'd aq. ammonium chloride the
mixture was partitioned between ethyl acetate and water. The crude
organic product was used as such in the next step.
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to 5 4-I2-(3,4-Bistdifluoromethoxyi-2-f4-(2-(2-trimeth,~Isil
ethoxymethoxy)-1 I I 3 3 3-hexafluoropropan 2
ylOphenyllethyl J'~pvridine
The crude product from Step 4 was refluxed in a mixture
of methanol ( 10 mL), THF' ( I 0 mL) and water (5 mL) containing
lithium hydroxyde hydrate ( 168 mg, 4 mmol) for 1.5 hours. After
cooling, sat'd aq. ammonium chloride (25 mL) was added and heating
was resumed far 20 minutes. The cooled mixture was partitioned
between ethyl acetate and water, and the crude organic product was
chromatographed on silica gel, eluting with a 2:1 mixture of ethyl
acetate and hexane affording the desired compound (327 mg, 50%) as a
colorless syrup.
1H NMR (400 MHz, acetone-d6) d 0.05 (s, 9H); 0.97 (t, 2H); 3.50 (m,
2H); 3.85 (t, 2H); 4.62 (t, 1H); 4.89 (s, 2H); 6.91 {t, Iarge J, 2H); 7.16
(d, 2H); 7.25 (d, 1H); 7.33 (d, 1H); 7.40 (s, IH); 7.55-7.65 (m, 4H);
8.36 (d, 2H).
to 6 4-I 2-(3.4-I~ifluoromethoxy~phenyl-2-(4-t 1,1,1,3
hexafluoro-2-hydrox ropan-2-vI)phen 1y ieth r~l }pyridine
The procedure for the removal of the SEM protecting
group described in Example 7, Step 5 was applied using the product of
Step 5 above as starting material. The title compound was purified by
chromatography, eluting with a 3:2 mixture of ethyl acetate and hexane,
and was obtained in 82% yield as a thick colorless syrup. Upon
trituration with ether and hexane, the title compound was obtained as a
white solid, mp 138-140~C.
1H NMR (400 MHz, acetone-d6) d 3.50 (d, 2H); 4.61 (t, IH); 6.92 {t,
Iarge J, 2H); 7.18 (d, 2H); 7.24 (d, 1H); 7.32 (d, IH); 7.39 (s, 1H); 7.51
(s, 1H, OH); 7.55 (d, 2H); 7.70 (d, 2H); 8.35 (d, 2H).
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EXAMPLE 1Q
4-f 2-(3.4-DifluoromethoxY)phenyl-2-[4-(1 1 1 3 3 3-hexafluoro-2-
hydrox~propan-2-~phen 1~~]~pvridine-N-oxide
To a solution of 4-{ 2-(3,4-difluoromethoxy)phenyl-2-[4-( 1, I,1,3,3,3-
hexafluoro-2-hydroxypropan-2-yl)phenyl]ethyl }pyridine
{132 mg) in dichloro methane (15 mL) was added m-chloroperoxy
benzoic acid 80-85% (65 mg) and the mixture was stirred at room
temperature. After 2 hours, a further 40 mg of oxidizing agent was
added. One hour later, calcium hydroxide ( 1 gram) was added, the
mixture was stirred for 5 minutes, then filtered through a bed of celite.
The filtrate was evaporated to a residue which was chromatographed on
silica gel, eluting with a 1:9 mixture of methanol and dichloromethane,
I5 affording the title compound {83 mg) as a white foamy solid.
1H NMR (400 MHz, acetone-d6) d 3.45-3.57 (m, 2H); 4.59 (t, 1H); 6.91
(t, large J, 1H); 6.94 (t, large J, 1H); 7.18 (d, 2H); 7.30 (d, 1H); 7.33 (d,
1H); 7.40 (s, 1H); 7.55 (d, 2H); 7.57 (s, IH, OH); 7.71 (d, 2H); 7.92 (d,
1H).
EXAMPLE 11
3.5-Dichloro-4-f 2-(3.4-DifluoromethoxY)phenyl~2-[4-(1 1 1 3 3 3-
hexafluoro-2-hvdroxYpropan-2-~phenvllethyl }pyridine
Step 1 3.5-Dichloro-4-f 2-f3,4-bis(difluoromethox~}-2-[4 j,2-(2-
trimeth lsilyl) ethoxymethoxy)-I I 1 3 3 3-
hexafluoropropan-2-vl)phen~l~ethvl } pyridine
To freshly prepared lithium diisopropylamide in THF {0.3
M, 5 mL, 1.5 mmol), at -78~C was added a solution of 3,5-dichloro-4-
picoline (295 mg, 1.82 mmol) in THF (5 mL). The dark yellow
solution was stirred at -78~C for 30 minutes, and was then added, via
canula, to a cold solution {-78~C) of chloride from Example A, Step 3
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(760 mg, 1.21 mmol) in THF { 10 mL). The resulting mixture was
warmed to room temperature and stirred for 2 days. Afer quenching
with sat'd aq. ammonium chloride, the mixture was partitioned between
ethyl acetate and water. The organic residue was chromatographed on
silica gel, eluting with a 1:5 mixture of ethyl acetate and hexane, to
afford the desired product (32 mg) as a colorless synzp.
1H NMR (400 MHz, acetone-d6) d 0.05 (s, 9H); 0.98 (t, 2H); 3.73 (m,
2H); 3.85 (t, 2H); 4.62 (t, 1H); 4.90 (s, 2H); 6.93 (t, large J, IH); 6.95
(t, large J, 1H); 7.24-7.30 {m, 2H); 7.36 (s, 1H); 7.51 (d, 2H); 7.61 (d,
2H); 8.43 (s, 2H).
A 60% recovery of starting chloride was also obtained.
Step 2 3.5-Dichloro-4-12-(3 4-DifluoromethoxY)phenyl 2 [4
I .1.1.3.3.3-hexafluoro-2-hvdroxypropan-2-yl)phenyll
ethyl ]~pvr~dine
To a solution of product from Step 1 (32 mg, 0.054 mmol)
in THF (0.8 mL) was added tetrabutylammonium fluoride 1 M in THF
(0.27 mL) and the mixture was refluxed for 2 hours. After cooling, the
mixture was quenched with sat' d aq. ammonium chloride and
partitioned between ethyl acetate and water. The crude organic product
was chromatographed on silica gel, eluting with a I :3 mixture of ethyl
acetate and hexane, to afford the title compound ( 11 mg) as a thick
colorless syrup.
IH NMR (400 MHz, acetone-d6) d 3.68 - 3.85 (m, 2H); 4.63 (t, 1H);
6.93 (t, Iarge J, 1H); 6.96 (t, Iarge J, 1H); 7.28 (s, 2H); 7.33 (s, 1H);
7.43 (s, IH, OH); 7.51 (d, 2H); 7.72 (d, 2H); 8.43 (s, 2H).
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Following the procedure described in Example 1 but
substituting o-toluic acid for carboxylic acid intermediate 1 and 4-[1-(3-
cyclopentyloxy-4-methoxyphenyl)-2-(4-pyridyl)ethyl]
benzenenesulfonamide from Step 6 for methanesulfonamide, the title
compound was obtained as a white solid (63%). 1H NMR (400 MHz,
acetone-d6): 8 1.5-1.6 (m, 2H), 1.65-1.85 (m, 6H), 2.23 (s, 3H), 3.40
(m, 2H), 3.70 (s, 3H), 4.45 (t, 1H), 4.75 (m, 1H), 6.81 (s, 2H), 6.90 (s,
1H), 7.10-7.20 (m, 4H), 7.30 (t, 1H), 7.50 (m, 3H), 7.95 (d, 2H), 8.30
(d, 2H).
PREPARATION OF INTERMEDIATES
Intermediate 1:
(R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzoic acid
o
CH30
v
~ ~N
W
OOH
Step 1: 2-(4-Bromophenyl)-1,3-dioxolane
A solution of 4-bromobenzaldehyde (66.5 g, 359 mmol),
ethylene glycol (22 mL, 395 mmol) and p-toluenesulfonic acid
monohydrate ( 120 mg) in benzene (400 mL) was refluxed for 3 hours
with concomitant Dean-Stark water trapping. The organic phase was
then washed successively with 5% aqueous NaHC03, water and brine,
dried (MgS04) and evaporated. The residue was distilled under reduced
pressure (bp: 112°C/0.4 mmHg) to afford the title compound as a
colorless liquid (79.8 g, 97%).
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Step 2: (1R, S,S~-N {(3R)-3-(3-Cyclopentyloxy-4-methoxyphenyl)-3-[4-
(1,3-dioxolan-2-yl)phenyl]-2-{4-pyridyl)propanoyl }-10,10-dimethyl-3-
thia-4-azatricyclo[5.2.1.01 ~5]decane-3,3-dioxide
A solution of 2-(4-bromophenyl)-1,3-dioxolane from Step
1 (55.3 g, 241 mmol) in THF (40 mL) was added to magnesium
turnings (6.I6 g, 254 lnnlol) in THF (140 mL) containing 1,2-
dibromoethane (0.1 mL) at a sufficient rate to maintain a gentle reflux.
The mixture was stirred at room temperature for 2 hours before the
solution was added dropwise to a 0°C solution of acyl sultam II
(Celltech, World Patent Application 95/I7386, 29 3une 1995)(43.2 g,
80.5 mmol) in THF (700 mL). The reaction mixture was stirred at
room temperature for 16 hours before 10% aqueous NH4C1 was added.
The mixture was extracted with EtOAc and the organic phase was
washed with water and brine, dried (MgS04) and evaporated. The
residue was recrystallized twice in EtOH to afford the title compound as
an off white solid (25.6 g, 46%).
Step 3:(R)-4-jl-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzaldehyde
n-Butyllithium (2.4 M solution in hexane; 10.6 mL, 25
mmol) was added dropwise to a 0°C solution of propanethiol (4.6 mL,
51 mmol) in THF (150 rnL). After 15 minutes, (1R, 5S7-N { (3R)-3-(3-
cyclopentyloxy-4-methoxyphenyl)-3-[4-( 1,3-dioxolan-2-yl)phenyl]-2-(4-
pyridyl)propanoyl }-10,10-dimethyl-3-thia-4-
azatricyclo[5.2.1.01 ~5]decane-3,3-dioxide from Step 2 (9.7 g, 14.1
mmol) was added as a solid and the reaction mixture was stirred at
room temperature for 3 days. The volatiles were then evaporated and
the resulting residue was dissolved in EtOH (80 nnl,) and water (40
mL). Sodium hydroxide (4.5 g, 113 mmol) was added and the mixture
heated to reflux for 2 hours. The reaction mixture was cooled to room
temperature and treated with HCl 6 N to pH 4.5 then heated to reflux
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for 1 hour. The reaction mixture was cooled to room temperature and
treated with NaOH 1 N to pH 14 then extracted twice with EtOAc. The
organic phase was washed with brine, dried (MgS04) and evaporated.
The residue was purified by flash-chromatography (silica gel, ether) to
afford the title compound as a white foam (2.3 g, 41 °yo). 1 H NMR (400
MHz, CDC13): 8 1.55 (m, 2H), 1.75 (m, 6H), 3.30 (m, 2H), 3.80 (s,
3H), 4.20 (t, I H), 4.60 (m, I H), 6.60 (s, 1 H), 6.65 (d, 1 H), 6.75 (d, 1
H),
6.90 (d, 2H), 7.35 (d, 2H), 7.75 (d, 2H), 8.40 (d, 2H), 9.95 (s, 1H).
Step 4: (R)-4-[1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]benzoic acid
A solution of NaC102 ( I49 mg, 1.64 mmol) and
NaH2P04~H20 {227 mg, 1.64 mmol) in water ( 1 mL) was added to a
I5 solution of aldehyde from Step 3 (508 mg, 1.27 mmol) and 2-methyl-2-
butene (0.94 mL, 8.9 mmol) in t-BuOH (6 mL). The reaction mixture
was stirred at room temperature for I9 hours before 25°lo aqueous
NH40Ac was added. The mixture was then extracted twice with EtOAc.
The organic phase was washed with brine, dried (MgS04) and
evaporated to afford the title compound as a white solid (540 mg). I H
NMR (400 MHz, CDCI3): ~ 1.55 (m, 2H), 1.75 (m, 6H), 3.35 (m, 2H),
3.80 (s, 3H), 4.20 (t, I H), 4.60 (m, 1 H), 6.60 (s, 1 H), 6.65 (d, 1 H), 6.75
(d, 1 H), 7.00 (d, 2H), 7.25 (d, 2H), 8.00 (d, 2H), 8.45 (d, 2H).
Intermediate 2:
{R)-4-[ I-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4
pyridyl)ethyl]phenylacetic acid
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Step l: 4-Bromophenylacetaldehyde
A solution of 4-bromostyrene (50.0 g, 0.273 mol) in
CH2C12 (550 mL) was added dropwise ( 1 h) to a solution of lead
tetraacetate (127 g, 0.273 moI) in trifduoroacetic acid (275 mL) at 10
°C. After completion of the addition, the reaction was left at room
temperature for 30 min and slowly poured into water (2 L). The
resulting mixture was stirred for 15 min and filtered through celite. The
aqueous layer was extracted with CHCl3 (2x) and the combined organic
extracts were successively washed with water (3x} and saturated aqueous
NaHCO3, dried (Na2S04) and concentrated. The crude yellow liquid
was purified by column chromatography on silica (EtOAc/hexane 1:9)
to afford the title compound as a pale yellow liquid (44.8g, 82%).
Step 2: 2-[(4-Bromophenyl)methyl]-1,3-dioxolane
A solution of 4-bromophenylacetaldehyde from Step 1
(44.5 g, 224 mmol), ethylene glycol ( 13.7 mL, 246 mmol) and p-
toluenesulfonic acid monohydrate (85 mg, 0.45 mmol) in toluene (300
mL) was refluxed for 3 h with concomitant Dean-Stark water trapping.
The reaction mixture was then washed successively with 5% aqueous
NaHC03 (2x}, water and brine, dried (MgS04) and concentrated. The
residue was distilled under reduced pressure (bp 110-115 °C/0.5 mmHg)
to afford the title compound as a colorless liquid (30.0 g, 55%).
1
C02H
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Step 3: (1R, SS)-N { {3R)-3-(3-Cyclopentyloxy-4-methoxyphenyl)-3-[4-
(1,3-dioxolan-2-ylmethyl)phenyl]-2-(4-pyridyl)propanoyl }-10,10-
dimethyl-3-thia-4-azatricyclo[5.2.1.01 ~5]decane-3,3-dioxide
A solution of 2-[(4-bromopheny!)methyl]-1,3-dioxolane
from Step 2 (27.2 g, 1 I2 mmol) in THF (20 mL) was added to
magnesium turnings (2.85 g, 117 mmol) in THF (70 mL) at a sufficient
rate to maintain a gentle reflux (a few crystals of iodine and heat were
necessary to initiate the reaction). The mixture was stirred at room
temperature for 2 h before it was added dropwise to a solution of acyl
sultam II (20.0 g, 37.3 mmol) in THF (350 mL) at 0 °C. The reaction
mixture was stirred at room temperature for 26 h and quenched by the
addition of saturated aqueous NH4CI. The organic Iayer was
concentrated and diluted with EtOAc, and the aqueous phase extracted
with EtOAc (2x). The combined organics were washed successively with
25% aqueous NH40Ac buffer, water and brine, dried (MgS04) and
evaporated. The residue was recrystallized in EtOH (a minimum of
CHC13 was necessary to insure dissolution) to afford the title compound
as a white solid ( 12.2 g, 46%).
Step 4: (R)-4-[1-{3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridy!)ethyl]phenylacetaldehyde diethyl acetal
n-Butyllithium (2.4 M solution in hexane; 13.2 mL, 31.3
mmol) was added dropwise to a solution of 1-propanethiol (3.47 mL,
38.3 mmol) in THF (160 mL) at 0 °C. After 30 min, (1R, SS)-N { (3R)-
3-(3-cyclopentyloxy-4-methoxyphenyl)-3-[4-( 1,3-dioxolan-2-
ylmethyl)phenyl]-2-{4-pyridyl)propanoyl }-10,10-dimethyl-3-thia-4-
azatricyclo[5.2.I.01~5] decane-3,3-dioxide from Step 3 (12.2 g, 17.4
mmol) was added as a solid and the reaction mixture was stirred at
room temperature for 2.5 h. The volatiles were then evaporated and the
resulting residue was dissolved in EtOH ( 100 mL) and water (50 mL).
Sodium hydroxide (5.57 g, 139 mmol) was added and the mixture
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heated to reflex for 2.5 h. The reaction mixture was cooled to room
temperature and treated with 6 N HCl to pH 4.5 then heated to reflex
for 2 h. The reaction mixture was cooled to room temperature and
treated with 1 N NaOH to pH 14, then extracted with EtOAc (3x). The
S combined organics were washed successively with 25% aqueous
NH40Ac buffer, water and brine, dried (MgS04) and concentrated. The
residue was purified by column chromatography on silica (acetone/ether
1:9--~ 1:4--~ 1:3) to afford the title compound as an off white gum ( 1. I7
g, 14%).
Step 5: (R)-4-[1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-(4-
pyridyl)ethyl]phenylacetaldehyde
A solution of {R)-4-[1-(3-cyclopentyloxy-4-
1 S methoxyphenyl)-2-(4-pyridyl)ethyl]-phenylacetaldehyde diethyl acetal
from Step 4 (1.14 g, 2.33 mmol), pyridinium p-toluenesulfonate (0.761
g, 3.03 mmol} in acetone (30 mL) and water (I.3 mL) was heated to
reflex for 20 h. It was then allowed to cool to room temperature,
diluted with EtOAc, successively washed with 5% aqueous NaHC03
(2x) and brine, dried (MgS04) and concentrated. The residue was
purified by column chromatography on silica {EtOAc/hexane
3:2-X7:3 X4:1 ~ 1:0) to afford the title compound as a white foam
(0.381 g, 39%).
Step 6: (R)-4-[ 1-(3-Cyclopentyloxy-4-methoxyphenyl)-2-{4-
pyridyl)ethyl]phenylacetic acid
A solution of sodium chlorite (80%; I31 mg, 1.16 mmol)
and sodium phosphate monobasic monohydrate {160 mg, 1.16 mmol) in
water (1.1 mL) was added to a solution of (R)-4-[1-(3-cyclopentyloxy-
4-methoxyphenyl}-2-(4-pyridyl}ettlyl]phenylacetaldehyde from Step 5
{371 mg, 0.893 mmol) and 2-methyl-2-butene (665 ~t,L, 6.25 mmol) in
t-BuOH (8 mL). The reaction mixture was stirred at room temperature
for 1.5 h before 25% aqueous NH40Ac buffer was added (a few drops
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of acetic acid were necessary to bring the pH at 7). The mixture was
then extracted with EtOAc (2x), and the combined organics were
washed successively with 25% aqueous NH40Ac buffer, water and
brine, dried (MgS04) and concentrated. The residue was purified by
column chromatography on silica {EtOAc containing 0.5% AcOH}.
Residual AcOH was co-evaporated with toluene (2x) to afford the title
compound as a white foam (319 mg, 83 %). 1 H NMR (400 MHz,
acetone-d6) : 8 I .50-1.61 (m, 2H), I .63-1.88 (m, 6H), 3 .40 (d, 2H),
3.54 {s, 2H), 3.70 (s, 3H}, 4.34 (t, J = 8 Hz, 1H), 4.75 (m, 1H), 6.78 (m,
2H), 6.90 {s, IH), 7.15 (d, J = 6 Hz, 2H}, 7.20 (d, J = 8 Hz, 2H), 7.30
(d, J = 8 Hz, 2H), 8.33 {d, J = 5 Hz, 2H).
