Note: Descriptions are shown in the official language in which they were submitted.
wo 94/25431 PCT/GB94/00886
21 61 544
,
CYCLOOXYGENASE AND 5-LIPOXYGENASE INHIBITING N(3-blphenylyl-1(s)-methyl-
2-propenyl) ACETOHYDROXAMIC ACID DERIVATIYES.
The present invention is concerned with hydlo~l~ic acid derivatives which are inhibitors of
the lipoxygenase and cyclooxygenase me~ ted arachidonic acid metabolic pathway, with
processes for their prepal~lion, with pharmaceutical formulations con~ ;ng saidderivatives and with their use in medicine.
European Patent Specification 0196184 describes hydlo~ ic acid derivatives having the
ability to inhibit the enzymes 5-lipo~ygenase and cyclooxygenase in the m~mm~ n
arachidonic acid cascade. The compounds in question include those of formula
/o~
Ar-Y-N,
` COR
wherein,
Y is C2 10 alkenylene;
Rl is Cl 4 alkyl, amino, Cl 4 alkylamino, or di-Cl 4 alkylamino;
and Ar is phenyl optionally substituted by one or more substit~ente independently selected
from:
(i) Cl 4 alkyl (which may itself be optionally substituted by one or more halogen
atoms), Cl 4 alkoxy, halo, nitro, amino, carboxy, C1 4 alkoxycarbonyl, and hydroxy;
(ii) phenyl optionally substituted by one or more substit-1ent~ independently selected
from those specified in (i).
WO 90/12008, WO 92/10469, and WO 92/01682 also disclose compounds having
lipoxygenase inhibitory activity.
We have now discovered a class of compounds related to those of EP0196184,
WO 90/12008, WO 92/10469, and WO 92/01682 having exceptionally good
SUBSTITUTE SHEET tRULE 26)
WO 94/25431 pcTlGs94loo886
21 61 ~44 -2-
pharmacological and physical p~up~llies; particularly, with respect to their potent 5-
lipoxygenase inhibitory activity, long duration of action and/or crystallinity.
According to the present invention, therefore, there is provided a compound of formula (I)
X ~ -.
N/\CH (I)
wherein Xis cyano, fluoro, or chloro;
or a salt, solvate, or physiologically functional derivative thereof.
In the alternative, the present invention provides a compound selected from:
(E)-N-[3-(4'-Cyano-3 -biphenylyl)- 1 (S)-methyl-2-propenyl]acetohydl o~ IiC acid;
(E)-N-[3-(4'-Fluoro-3-biphenylyl)-1(S)-methyl-2-propenyl]acetohydrux~llic acid;
(E)-N-[3 -(4'-Chloro-3-biphenylyl)- 1 (S)-methyl-2-~ropellyl]acetohydl O~llliC acid;
and salts, solvates and physiologically functional derivatives thereof.
Salts of compounds of formula (I) which are suitable for use in medicine are those wherein
the counterion is pharmaceutically acceptable. However, salts having non-pharmaceutically
acceptable counterions are within the ambit of the present invention, either for use as
interme~ tes in the pfepal~Lion of compounds of formula (I) and their pharm~ce~ltic~lly
acceptable salts, solvates, and physiologically functional derivatives.
Salts according to the invention include ammonium salts, alkali metal salts such as those of
sodium and pot~csi~lm, alkaline earth metal salts such as those of calcium and m~gnecillm,
salts with organic bases such as dicyclohexylamine and N-methyl-D-glucamine, and salts
with amino acids, such as arginine and Iysine.
SUBSTITUT~ SHEET (RU~E 26
WO 94125431 2 1 6 ~ 5 4 4 PCT/GBg4/00886
- 3 -
By the term physiologically functional derivatives is meant chemical derivatives of
compounds of formula (I) which have the same physiological function as the free
compound of formula (I), for example, by being convertible in the body thereto. According
to the present invention, examples of physiologically functional derivatives include
compoun,ds of formula (I) in which the hydroxyl of the hyd,ox~",ic acid functional group
has been converted to a urethane, an alkyl ether, or an ester.
The definition of the compounds of the invention provides compounds of formula (I) in the
(S) forrn. However, the present invention also provides compounds of formula (I) as
mixtures of the (R) and (S) forms, provided that the (R) form conctihltes less than 50% of
the mixture.
As mentioned hereinbefore, compounds of for nula (I) and salts, solvates, and
physiologically functional derivatives thereof have use in the prophylaxis and treatment of
clinical conditions for which an inhibitor of the lipoxygenase or cyclooxygenase medi~ted
arachidonic acid metabolic pathway is in~ic~ted7 as d~monctrated hereinafter in the 5-
lipoxygenase and cycloo~ygenase inhibition assays in which ~eplesc~ re compounds of
the present invention have been shown to be active. For eY~mple, the ability of compounds
of formula (I) to inhibit the lipoxygenase and cyclooxygenase medi~ted arachidonic acid
metabolic pathways, renders them useful for the prophylaxis and l,e.~l.n~..,l of spasmogenic
conditions, allergic conditions, tumour formation, conditions involving blood platelet
aggregation, and infl~rnm~tory conditions.
Examples of spasmogenic conditions are those involving smooth muscle tissue, especially
airway smooth muscle constriction such as asthma (including idiopathic bronchial asthma),
bronchitis and arterial smooth muscle constriction such as coronary spasm (including that
associated with myocardial infarction, which may or may not lead to left ventricular failure
resulting in cardiac asthma), icçh~ induced myocardial injury, and cerebral spasm or
'stroke' (which may lead to central nervous pathophysiology). Other examples include
bowel disease caused by abnormal colonic mllcclll~r contraction such as the conditions
known as 'irritable bowel syndrome', 'spastic colon' and 'mucous colitis'.
Examples of allergic conditions are extrinsic asthma, allergic skin dise~ces having a total or
partial allergic origin, such as ec7.em~ allergic bowel dice~ces (including coeliac disease),
allergic eye conditions, such as hayfever (which may additionally or alternatively affect the
upper respiratory tract), allergic rhinitis, and allergic conjunctivitis.
SUeSTlTUTE SHEE~ (RULE 26~
WO 94125431 2 1 6 1 5 4 4 PCT/GB94/00886
- 4 -
Examples of tumours are skin neoplasms, mastocytoma and other forms of cellular
proliferation, both benign and m~lign~nt. It is to be noted that the effectiveness of the
present compounds in the prophylaxis and treatment of tumours may arise from plopwlies
in addition to 5-lipoxygenase inhibition which also inhibit cell proliferation.
Examples of conditions involving blood platelet aggregation are those resulting from
thrombosis, including 'strokes' having a total or partial thrombotic origin, coronary
thrombosis, phlebitis and phlebothrombosis (the latter two conditions also possibly being
associated with inflAmmAflon).
Examples of infl~mm~tory conditions are those of the lungs, joints, eyes, bowel, skin, and
heart; particularly those associated with the infiltration of leucocytes into inflamed tissue.
TnflAmm~tory lung conditions include asthma, adult respiratory distress syndrome,
bronchitis and cystic fibrosis (which may additionally or alternatively involve the bowel or
other tissue(s)). TnflAmm~tory joint conditions include rheumatoid arthritis, rheum~toid
spondylitis, osteoarthritis, gouty arthritis and other arthritic conditions. TnnA~ tory eye
conditions include uveitis (in~ inp~ iritis) and conjunctivitis. TllnAI~llllAtory bowel
conditions include Crohn's disease, ulcerative colitis and distal proctitis. TnflAmmAtory skin
~i~e~es include those associated with cell proliferation, such as psoriasis, eczema and
dermatitis (whether or not of allergic origin). TnflAmm~tory conditions of the heart include
coronary infarct damage. Other inflAmm~tory conditions include tissue necrosis in chronic
inflAmm~tion, endotoxin shock, smooth muscle proliferation disorders (for example,
restenosis following angioplasty), and tissue rejection following transplant surgery.
Accordingly, the present invention provides a method for the prophylaxis or lleallllellL of a
clinical condition in a m~mm~l such as a human, for which an inhibitor of the lipo~ygellase
or cyclooxygenase mediated arachidonic acid metabolic pathway, for example, a 5-lipoxygenase or cyclooxygenase inhibitor, is indicated; which comprises ~(lmini~tration of a
therapeutically effective amount of a compound of formula (I), or a pharmaceutically
acceptable salt, solvate, or physiologically functional derivative thereof. The present
invention further provides a method for the prophylaxis or Irea~llltll~ of a clinical condition
in a m~mm~l such as a human, which clinical condition is a spasmogenic condition, an
allergic condition, tumour formation, a condition involving blood platelet agglega~ion, or
an infl~mm~tory condition; which comprises ~mini~tration of a therapeutically effective
amount of a compound of formula (I), or a pharmaceutically acceptable salt, solvate, or
physiologically functional derivative thereof.
SUBSTIT~.JTE StlEET (RULE 26
WO 94/25431 2 1 6 1 ~ 4 4 PCT/GB94/00186
In the alternative, there is also provided a compound of formula (I), or a pharmaceutically
acceptable salt, solvate, or physiologically functional derivative thereof for use in medical
therapy; particularly, for use in the prophylaxis or treatm~nt of a clinical condition in a
m~mm~l such as a human, for which an inhibitor of the lipoxygenase or cyclooxygenase
mediated arachidonic acid metabolic pathway, for example, a 5-lipoxygenase or
cyclooxygenase inhibitor, is indicated; for example a spasmogenic condition, an allergic
condition, tumour formation, a condition involving blood platelet aggregaLion~ or an
,;.(ory condition.
The amount of a compound of formula (I), or a pharm~ceutically acceptable salt, solvate or
physiologically functional derivative thereof which is required to achieve a therapeutic
effect will, of course, vary with the particular compound, the route of a~ ion, the
subject under llea~".~, and the particular disorder or disease being treated. A suitable
daily dose for a m~mm~l suffering from, or likely to suffer from, any of the clinical
conditions described heleinbero-e is in the range 0.1~g-50mg of compound/kilogran
bodyweight. In the case of systemic a~mini~tration~ the daily dose is typically in the range
0.05 - 50mg of compound/kilogram bodyweight, the most plere,led dosage being from
0.05 to 20mg/kg bodyweight, for example, from 0.1 to 10mg/kg, adminietered as two or
three sub-doses daily. In the case of topical a~lmini~tration, e.g. to the skin or eye, a
suitable dose is in the range 0.1 ~g - 1 OO~lg of base per kilogram, typically about 0.1 ~lg/kg.
In the case of oral dosing for the prophylaxis or Ll~l~..e..l of airway smooth muscle
constriction, for example, in asthma or bronchitis, a suitable dose of the compound of the
invention may be as specified in the p.t;ceding paragraph, but plert.~bly is from 0. lmg to
1 Omg of compound/kilogram bodyweight, the most prerelled dosage being from 0. lmg to
5mg/kg bodyweight. In the case of pulmonary a~iminictration~ the dose is typically in the
range 2~g - 100mg/kg, preferably, from 511g to 5mg/kg, for example from 0.01 to 1 mg/kg.
The present invention also provides the use of a compound of formula (I), or a
pharmaceutically acceptable salt, solvate, or physiologically functional derivative thereof in
the m~nllf~ctllre of a medicament for the prophylaxis or treatmP,nt of a clinical condition for
which an inhibitor of the lipoxygenase or cyclooxygenase mediated arachidonic acid
metabolic pathway, for example, a 5-lipoxygenase or cyclooxygenase inhibitor, is indicated;
for exarnple a spasmogenic condition, an allergic condition, tumour formation, a condition
involving blood platelet aggregation, or an infl~mm~tory condition.
SUBS'ITUTE SHEET (RULE 26~
WO 94/25431 PCT/GB94/00886
21 61 544 -6
While it is possible for the compound of formula (I), or a salt, solvate, or physiologically
functional derivative thereof to be a~mini~tçred alone, it is pre~lable to present it as a
pharm~ce~ltical formulation. Accordingly, the present invention further provides a
pharm~ce~ltical formulation comprising a compound of formula (I) or a pharmaceutically
acceptable salt, solvate, or physiologically functional derivative thereof, and a
pharmaceutically acceptable carrier or excipient, and optionally one or more other
therapeutic ingredients.
Hereinafter, the term "active ingredient" means a compound of formula (I), or a
pharmacelltically acceptable salt, solvate, or physiologically functional derivative thereof.
The carrier or excipient must, of course, be col"paLil,le with the other ingredients in the
formulation and must not be detrimental to the recipient. The active ingredient may
comprise from 0.1% to 99.9% by weight of the formulation. Typical unit doses of a
formulation according to the invention contain from 0.0lmg to lg of the active ingredient.
For topical ~rlmini~tration, the active ingredient preferably con~titlltes from 1% to 2% by
weight of the formulation, but the active ingredient may constitute as much as 10% w/w.
Formulations suitable for nasal or buccal atlminietration~ typically contain from 0.1 to 20%
w/w, for example, 2% w/w of the active ingredient.
Formulations according to the invention include those in a form suitable for oral,
pulmonary, ophthalmic, rectal, parenteral (inclll~ing subcutaneous, intr~m--~c~ r and
intravenous), intra-articular, topical, or nasal/buccal ~rlmini~tration.
The formulations of the invention may conveniently be presented in unit dosage form and
may be prepared by any method well known in the art of pharmacy. All such methods
include the step of bringing the active ingredient into association with a carrier which
con.ctitute~ one or more accessoly ingredients. Optionally, the particle size of the active
ingredient may be reduced before formulation, for example, by micronisation. In general,
the formulations are plep~d by uniformly and intim~tely bringing the active ingredient
into association with a liquid carrier or a finely divided solid carrier, or both, and then, if
desired, shaping the product into the required form.
Formulations according to the present invention which are suitable for oral ~flmini~tration
may be in the form of discrete units such as capsules, cachets, tablets, or lozenges, each
cont~ining a predetermined amount of the active ingredient; in the form of a powder or
SUBS~ITUTE SHEET (RULE 26~
wO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 7 -
granules; in the form of a solution, suspension, or a microfine suspension in an aqueous or
non-aqueous liquid; or in the form of an oil-in-water or water-in-oil emulsion. The active
ingredient may also be in the form of a bolus, electuary, or paste.
A tablet may be made by compressing or moulding the active ingredient, optionally with
one or more accessory ingredients. Col,lp,essed tablets may be prepaled by co",~ures~h~g~
in a suitable machine, the active ingredient in a free-flowing form such as a powder or
granules, optionally mixed with a rli~integrant~ compression aid, binder, lubricant, inert
diluent, and/or surface active or dispersing agent. Moulded tablets may be made by
moulding, in a suitable m~hine, a mixture of the powdered active ingredient and a suitable
carrier moistened with an inert liquid diluent.
Formulations for rectal a-l".;";.~ Lion may be in the for n of a suppository incorporating
the active ingredient and a carrier such as cocoa butter, or in the form of an enema.
Formulations suitable for parenteral admini~tration typically comprise a sterile aqueous or
non-aqueous prep~ralion such as an emulsion, suspension, or colloid of the active
ingredient which is preferably isotonic with the blood of the recipient. Such formulations
may also be freeze-dried and then recon~titllted by addition of a sterile fluid shortly before
a~mini~tration.
Formulations suitable for intra-articular a-lmini~tration may be in the form of a sterile
aqueous plepa,~lion of the active ingredient, which latter may be in microcrystalline form,
for example, an aqueous microcrystalline suspension.
Liposomal formulations and biodegradable polymer systems may also be used, for example
to present the active ingredient for parenteral, intra-articular and ophthalmic a-lmini~tration.
Formulations suitable for topical a(1mini~tration include liquid and semi-liquid p,ep~lions
such as linimPnt~, lotions and applications; oil-in-water and water-in-oil emulsions such as
creams, ointmP-nt~ and pastes; and solutions and suspensions such as drops. For example,
for ophthalmic a~lmini~tration~ the active ingredient may be presented as aqueous eye drops,
for example, in the form of a 0.1 - 1.0% w/v solution.
Suitable formulations for a~mini~tration by inhalation include fine particle dusts or mists
which may be generated by means of various types of metered dose pressurised aerosols,
SUeSTlT~JTE SHEET (RULE 26j
WO 94/25431 21 6 1 5 4 4 8 - PCT/GB94/00886
nebulisers, or in~uffi~tors.
For pulmonary admini~tration via the mouth, the particle size of the powder or droplets is
typically in the range 0.5 - 10~m, preferably 1 - 511m, to ensure delivery into the bronchial
tree. For nasal a~mini~tration, a particle size in the range 10 - 50011m is prerel-ed to ensure
retention in the nasal cavity. --
Metered dose inhalers are pressurised aerosol dispensers, typically co~ g a suspensionor solution formulation of the active ingredient in a liquefied propellant. During use, these
devices discharge the formulation through a valve adapted to deliver a metered volume,
typically from 10 to 150~1, to produce a fine particle spray cont~ining the active ingredient.
Suitable propellants include certain chlorofluorocarbon compounds, for example,
dichlorodifluorometh~ne, trichlorofluorometh~ne~ dichlorotetrafluoroethane and mixtures
thereof. The formulation may additionally contain one or more co-solvents, for example,
ethanol, surfact~nt~, such as oleic acid or sorbitan trioleate, anti-oxidants and suitable
flavouring agents.
Nebulisers are co"""ercially available devices that ~ sro"n solutions or suspensions of the
active ingredient into a therapeutic aerosol mist either by means of acceleration of a
co",plessed gas through a narrow venturi orifice, typically air or oxygen, or by means of
ultrasonic agitation. Suitable formulations for use in nebulisers consist of the active
ingredient in a liquid carrier and comprising up to 40% w/w of the formulation, preferably
less than 20% w/w. The carrier is typically water or a dilute aqueous alcoholic solution,
preferably made isotonic with body fluids by the addition of, for example, sodium chloride.
Optional additives include preservatives if the formulation is not prepared sterile, for
example, methyl hydroxy-benzoate, anti-oxidants, flavouring agents, volatile oils, buffering
agents and surfactants.
Suitable formulations for admini~tration by in~ffi~tion include finely commin-lted powders
which may be delivered by means of an in~llffl~tor or taken into the nasal cavity in the
manner of a snuff. In the in~uffi~tor, the powder is contained in capsules or cartridges,
typically made of gelatin or plastic, which are either pierced or opened _ situ and the
powder delivered by air drawn through the device upon inhalation or by means of a
manually-operated pump. The powder employed in the in~llffl~tor consists either solely of
the active ingredient or of a powder blend comprising the active ingredient, a suitable
powder diluent, such as lactose, and an optional surfactant. The active ingredient typically
SUBSTITUTE SHEET (RULE 26)
WO 94/2~431 2 1 6 1 5 4 4 PCT/GB94/00886
comprises from 0.1 to 100% w/w of the formulation.
In addition to the aforementioned ingredients, formulations according to the invention may
include one or more additional ingredients such as diluents, buffers, flavouring agents,
binders, co~ )les~;on aids, ~ ntegrants~ surface active agents, thickeners, lubricants,
preservatives, for example, methyl hydroxyb~n~o~te, anti-oxidants and emulsifying agents.
The compounds of the invention may advantageously be employed in colllbhlalion with one
or more other therapeutic ingredients selected from an antibiotic (for example, an anti-
bacterial), anti-fungal, or anti-viral agent, an anti-hi~t~mine (particularly a peripherally-
acting anti-hi.~t~mine), or a non-steroidal anti-infl~mm~tQry drug (NSAID).
The compounds of these combinations may be ~lmini~t~red ~imlllt~n~ously, for example, in
the same formulation or in separate formulations, or sequentially within a sufficiently short
time interval to achieve the desired combined therapeutic effect. When the compounds are
employed in the same formulation, a formulation according to the invention may contain, in
addition to a compound of the invention, the further ingredient(s).
According to a further aspect of the invention, there is provided a process for plepa,illg the
compounds of formula (I), or salts, solvates, or physiologically functional derivatives
thereof which comprises reacting a compound of formula (II)
" ~: ~/ (Il)
either as the (S) enantiomer or a mixture of the (R) and (S) enantiomers, wherein X is as
defined for the compound of formula (I), with a suitable agent or agents to effect
conversion of the N-hydrogen to an N-C(O)CH3 group;
and optionally (a) separating the mixture of enantiomers so obtained and/or (b) converting
the compound of formula (I) so formed to a collt;~l~onding salt, solvate or physiologically
functional derivative thereof.
Conversion of the N-hydrogen to an N-C(O)CH3 group is typically carried out by treating
SUBS~'TUTE SHEET (RULE 26~
wO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 10-
a compound of formula (II) with an acylating agent, for example, an approp,iate anhydride
or activated acid, such as an acid halide, for example, acetyl chloride. This reaction is
suitably effected in an inert solvent, such as a halohydrocarbon, for example,
dichlor~...elh~ne, or an alkylbenzene, for example, toluene, at a tell~pel~ re in the range
-10C to 150C, for example 0-25C in the presence of an organic base, such as atrialkylamine, for example, triethylamine. Any N,O-diacylated product of this reaction may
be mono-O-deacylated, suitably by treatment with an inorganic base, for example,potassium carbonate, or by treatment with a suitable enzyme, such as a lipase.
Where the compound of formula (II) is present as the (S) enantiomer, the compound of
formula (I) may be obtained as the (S) enantiomer. Where the compound of formula (II) is
present as a mixture of the (S) and (R) enantiomers, the compound of formula (I) may be
obtained as the (S) enantiomer by: (i) sep&~lhlg the enantiomers obtained from the
acylation reaction by any suitable method; (ii) ~.ili"g the mono-O-deacylation reaction by
treatment with an enzyme capable of selectively reacting with the (S) enantiomer, for
example a lipase, to produce a mixture of the compound of formula (I) as the (S)enantiomer and the N,O-diacylated (R) enantiomer which can then be separated, for
example by cl~c",alography; (iii) effecting the mono-O-deacylation reaction by treatment
with an enzyme capable of selectively reacting with the (R) enantiomer, for example a
lipase, to produce a mixture of the N,O- diacylated compound of formula (I) as the (S)
enantiomer and the N-acylated (R) enantiomer which can then be separated, for example by
chromatography. The separated N,O-diacylated product of this reaction may then be
mono-O-deacylated by any of the methods described above to yield the compound offormula (I) as the (S) enantiomer.
Compounds of formula (II) and salts thereof may be prepared from the corresponding
compound of formula (III)
X
, i P'
OP"
SUBSTI,'JTE SHEET (RULE 26)
WO 94125431 PCT/GB94/00886
-11- 2~61544
wherein X is as defined for a compound of formula (I), P' is a protecting group, such as an
alkoxycarbonyl group, for example, -CO2CH3, a cyclic ether, for example,
tetrahydropyran, or -butoxycarbonyl (Boc) and P" is a protecting group as described for P'
or is hydrogen. The conversion to a compound of formula (II) is suitably effected by acid
or base hydrolysis as would be understood by the person skilled in the art. For example,
where the -N(Boc)O(Boc) or -N(Boc)OH compound of formula (m) is used, the
compound of forrnula (II), or a salt thereof, may be plel)~ed by lre~l..,f...l with an acid,
such as an arylsulphonic acid, for ~,A~llple, para-tol~nesl~lphonic acid; in a non-polar
solvent, for example, toluene; at a moderate telllper~ re, suitably in the range 10-100, for
example, 50-60C. The resulting salt of the compound of formula (II) may then optionally
be hydrolysed to release the free base, for example, by chromatography on silica or by
treatment with an inorganic base, such as a carbonate, for example, sodium carbonate.
Compounds of formula (III) may be obtained either by:
(i) reaction of the corresponding compound of formula (IV)
CH2=CEI-CH(CII3)-N(P')OP' (IV)
wherein P' is as defined above, with a compound of formula (V)
~ (V)
wherein X is as defined for the compound of formula (I) and L is a suitable leaving
group, for example, a halogen, (typically bromo or iodo) or a substituted sulphonate,
for example, trifluorometh~neslllfonate; typically at elevated temperature, for
example, 50-150C, in a polar solvent, for example, N,N-dimethylformamide, in the
presence of a catalyst, such as p~ll~(lillm (II) acetate with tri(o-tolyl)phosphine, and a
suitable base, such as a trialkylamine, for example, triethylamine; or
(ii) reaction of a compound of formula (VI)
SUBSTITUTE SHEE~ (RULE 26)
.
Wo 94/25431 pcTlGs94loo886
~1 61 544 -12
X~ OH
CH3 (VI)
wherein X is as defined for formula (I), with a compound of formula HN(P')OP'
wherein P' is as defined for the compound of formula (III). This reaction may beeffected under Mitsunobu conditions, for example in the presence of diethyl
azodicarboxylate (DEAD) or diisopropyl azodicarboxylate (DIAD) and
triphenylphosphine (PPh3); in a non-polar solvent, such as toluene; at low
te~ )elalllre, ie -20 to 50C, for CA~II~ e in the region of 0C. Alternatively, this
reaction may be effected by activation of the compound of formula (VI), for example
by esterification of the hydroxyl group, typically using an acid anhydride (eg. acetic
anhydride) or an acid halide (e.g. chloroacetyl chloride); in the presence of a base
(eg. 4-dimethylaminopyridine, DMAP); and a catalyst, for example,
tetrakis(triphenylphosphine) p~ m (O); in a non-polar solvent, such as
tetrahydrofuran (THF); at elevated temperature, for example, 40-120C.
Compounds of formula (VI) may be prepared either:
(i) by reduction of the corresponding compound of formula (VII)
X ~ (Vll)
wherein X is as defined for the compound of formula (I). The reduction may be done
in such a way that a chiral alcohol of formula (VI) is obtained, for example, (a) by
using a chiral ind~lçing catalyst, suitably an oxazaborolidine CBS catalyst (E.J. Corey
et al Tet Letters 31(5), 611 (1990)) with the reducing agent, suitably catechol borane
in an inert solvent, such as a cyclic ether (eg.THF) or an alkylbenzene (eg. toluene) at
SUBST~TUTE St~EET (RULE 26~
WO 94/25431 - 13 - 2 1 6 1 5 4 4 PCT/GB94/00886
low te~l-pe~aL~Ire, for example in the range -100C to 50C, or (b) by an enzymic
reduction process. Alternatively, the reduction may be carried out to give the
racemic alcohol of formula (VI) using conventional reducing agents of organic
ch~mi~try for example, treatment with sodium borohydride in a polar solvent, such as
an alcoholic solvent, at low temperature, for example in the range -50C to 30C. If
desired, the enantiomeric mixture of compounds of formula (VI) so obtained may be
separated into the individual enantiomers by any suitable method, for example, by an
enzymic resolution process, typically an enzyme catalysed acyl-transfer or hydrolysis
reaction effected by treating the racemic compound of formula (VI) with an acyl
donor, such as an enol ester (eg. vinyl acetate), an activated ester (eg.
trifluoroethylbutyrate), or an acid anhydride (eg. succinic anhydride),either in the
presence of a suitable enzyme capable of acylating only one enantiomer, such as a
lipase, in an inert solvent, such as an aromatic solvent (eg. toluene), at non-extreme
temperature, for example in the range -20C to 60C, or followed by Ll ea~ ;l.L with
a suitable enzyme capable of selectively hydrolising one acylated enantiomer, such as
a lipase. The resulting enantiomers may then be separated because one of them ispresent in acylated form, by any applopliate method, for example, by
cluolllaLography. If desired, the unwanted enantiomer may be "recycled", for
example by racemic deacylation, suitably by hydrolysis; or
(ii) by reaction of the applop-iate compound of formula (V) as defined above with a
compound of formula (VIII)
CII2=CII-CH(CEI3)-OP' (vm)
wherein P' as hereinbefore defined. This reaction may be carried out in the presence
of a suitable catalyst system, for example, p~ m (II) acetate/tri-(o-
tolyl)phosphine, and a base, such as a trialkylamine, for example, triethylamine.
Subsequent removal of the hydroxyl protecting group P' may be effected by any
suitable method, such as hydrolysis, for example, acid hydrolysis; or
(iii) by reaction of the appropriate compound of formula (V) as defined above with
crotonaldehyde (CH3CH=CHCHO) and then isomerising the resulting allylic alcohol
to give the desired compound of formula (VI). The reaction with crotonaldehyde
may be carried out typically by lithiation of the compound of formula (V), for
example by treatment with butyl lithium at low temperature (suitably below -50C)
SUBSTITUTE SHEET (RULE 26~
WO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 14-
followed by treatment with the crotonaldehyde. The isomerisation may be carried
out by l,e~ .,l with acid, for example hydrochloric acid at moderate temperature.
The compound of formula (VII) may be p,epared by reaction of the corresponding
aldehyde of formula (IX)
~,
,~ ~"CHO
~,~ (IX)
wherein X is as defined for the compound of formula (I), with a compound of formula (X)
0~
P(R')2
I ~ -CH3
wherein R' is Cl 4 alkyl or, alternatively with acetone; in the presence of a base, such as
sodium carbonate; in a polar solvent, such as THF, at a non-extreme temperature, for
example -50 to 30C.
Compounds of formula (Vm) and HN(P')OP' may be prepared from the corresponding
commercially available alcohol and hydroxylamine by standard protecting group chemistry.
Compounds of formula (IX) may be prepared from compounds of formula (V) as defined
above, typically by lithiation (for example with n-butyl lithium at low temperature, ie -100
to -20C) followed by reaction with N,N-dimethylru~,a",ide (DMF).
Compounds of formula (X) are co"l"le, cially available or may be prepared by methods well
known to the person skilled in the art or by methods readily available from standard
chemical literature.
Compounds of formula (IV) may be obtained by one ûr more of the methods described in
SUi~STlTUTE SHEET (RULE 26~
WO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 15 -
EP 0384594.
Compounds of formula (V) may be obtained commercially or prepared, for example, by
coupling a compound of formula (XI)
X' ~ --B(OH)2 (XI)
wherein X' is as defined for X in the compound of formula (I), or is a suitable precursor
therefor, or a suitably protected form thereof, with a compound of forrnula (~I)
L' ~ ,L ~II)
wherein L is as defined above for formula (V) and L' is either the same as L or is a di~l elll
leaving group as understood by a skilled person. This coupling may suitably be effected in
the presence of a suitable catalyst, for example, tetrakis (triphenylphosphine) p~ m (0)
and an inorganic base, for example, sodium carbonate.
Alternatively, compounds of formula (V) may be prepared by coupling a compound of
formula (XII) as heleinbcfore defined with the appropliate organometallic reagent (for
example, the applopliately substituted PhMgY or PhZnY, where Y is a halogen) which
may be prepared in si~u from the corresponding halide by treatment with the metal (e.g. Mg
or Zn). The coupling may be effected in an inert solvent, for example, T~, in the presence
of a catalyst, for example, 1,4-bis(diphenylphosphine)butane p~ m (0) dichloride,
p~ dillm acetate, or tetrakistriphenyl phosphine p~ m (0), at non-extreme
temperature, for example 0-60C.
The enantiomeric compounds of the invention may be obtained (a) by separation of the
components of the collespondil1g racemic mixture, for example, by means of a chiral
chromatography column, enzymic resolution methods as described above, or preparing and
separating suitable diastereoisomers, or (b) by direct synthesis from the appropliate chiral
SUB5TITUTE SHEET (RULE 26)
WO 94125431 ~CTIGB94100886
~ b~ 544 -16-
interrnediates by the methods described above.
Optional conversion of a compound o~ formula (I) to a co,l~spol~d,~,g salt may
conveniently be effected by reaction with the appropriate base Optional conversion of a
compou ,nd of formula (I) to a corresponding solvate or physiologically functional derivative
may be effected by methods known to those skilled in the art.
According to a further aspect, the present invention provides novel intermedi~te~ for the
prepal~lion of compounds offormula a), for example:
(a) Compounds of formula (II) as defined above, or a salt thereof; particularly, a
compound selected from:
(E)-N-~3-(4'-Cyano-3 -biphenylyl)- 1 (S)-methyl-2-propenyl]hydroxylamine;
(E)-N-[3-(4'-Cyano-3-biphenylyl)-l(R,S)-methyl-2-prope~yl]hydroxylamine;
(E)-N-[3 -(4'-Fluoro-3 -biphenylyl)- 1 (S)-methyl-2-propenyl]hydroxylamine;
(E)-N-[3-(4'-Fluoro-3-biphenylyl)-1(R,S)-methyl-2-propenyl]hydroxylamine;
(E)-N-[3-(4'-Chloro-3-biphenylyl)-1(S)-methyl-2-propenyl]hydroxylamine; and
(E)-N-[3 -(4'-Chloro-3 -biphenylyl)- 1 (R, S)-methyl-2-propenylJhydroxylamine;
(b) Compounds of formula (III) as defined above; particularly, a compound selected
from:
(E~-N,O-Bis(t-butoxycarbonyl)-N-[3-(4'-cyano-3-biphenylyl)- 1 (S)-methyl-2-
propenyl]hydroxylamine;
(E)-N,O-Bis(t-butoxycarbonyl)-N-[3-(4'-cyano-3-biphenylyl)-l(R,S)-methyl-2-
propenyl~hydroxylamine;
(E)-N,O-Bis(t-butoxycarbonyl)-N-[3 -(4'-fluoro-3 -biphenylyl)- 1 (S)-methyl-2-
propenyl]hydroxylamine;
(E)-N,O-Bis(t-butoxycarbonyl)-N-[3-(4'-fluoro-3-biphenylyl)-1(R~S)-methyl-2-
propenyl]hydroxylamine;
(E)-N,O-Bis(t-bulo~-yc~bonyl)-N-[3-(4'-chloro-3-biphenylyl)-1 (S)-methyl-2-
propenyl]hydroxylamine; and
(E)-N,O-Bis(t-butoxycarbonyl)-N-[3-(4'-chloro-3-biphenylyl)- 1 (R,S)-methyl-2-
propenyl]hydroxylamine;
(c) Compounds of formula (VI) as defined above; particularly, a compound selected
from:
SUBSTIT~JTE SHEE~ (RULE 26)
WO 94/25431 PCT/GB94/00886
1 544
- 17-
(E)-4-(4'-Cyano-3 -biphenylyl)-3 -buten-2(S)-ol;
(E)-4-(4'-Cyano-3 -biphenylyl)-3 -buten-2(R)-ol;
(E)-4-(4'-Cyano-3-biphenylyl)-3-buten-2(R,S)-ol.
(E)-4-(4'-Fluoro-3 -biphenylyl)-3 -buten-2(S)-ol;
(E)-4-(4'-Fluoro-3 -biphenylyl)-3 -buten-2(R)-ol;
(E)-4-(4'-Fluoro-3 -biphenylyl)-3 -buten-2(R, S)-ol.
(E)-4-(4'-Chloro-3-biphenylyl)-3 -buten-2(S)-ol;
(E)-4-(4'-Chloro-3-biphenylyl)-3-buten-2(R)-ol; and
(E)-4-(4'-Chloro-3-biphenylyl)-3-buten-2(R,S)-ol.
(d) Compounds of formula (VII) as defined above; particularly,a compound selected
from:
(E)-4-(4'-Cyano-3 -biphenyiyl)-3 -buten-2-one;
(E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-one; and
(E)-4-(4'-Chloro-3 -biphenylyl)-3 -buten-2-one .
(e) Compounds of formula (IX) as defined above; particularly, a compound selected
from:
3 '-(4'-Cyanophenyl)b.on7~1~1çhyde.
3 '-(4'-Fluorophenyl)b~n7~1dehyde.
3'-(4'-Chlorophenyl)b.on7~1d~hyde.
For a better underst~ntling of the invention, the following Examples are given by way of
illustration.
SY~ l ~ l lC EXAMPLES
Synthetic Example l
P, epa1 ~lion of (E)-N-[3 -(4'-Cyano-3-biphenylyl)- l (S)-methyl-2-propenyl] acetohyd, oxa",ic
acid
(a) 4-Cyanophenylboronic acid
A cooled (-100C), stirred solution / suspension of 4-bromobel zoni~lile (9.lO g,
Aldrich) in dry tetrahydrofuran (250 ml, Fluka) and under a dry nitrogen
SUB~TITUTE SHEET (:~ULE 2b~
WO 94/25431 21 61 5 4 4 PCT/GB94/00886
atmosphere, was treated dropwise over 20 minutes with a 1.6M solution of n-
butyllithium in hexane (31.3 ml, Fluka). Stirring was continued at -100C for a
further 10 minutes and then the reaction mixture was t~ relled over 15 minutes
into a cooled (-100C), stirred mixture of tri(iso-propyl)borate (23 ml, Aldrich) and
dry tetrahydrofuran (2 ml) under a dry nitrogen atmosphere. Stirring was continued
at -100C for a further 10 minutes then the temperature was allowed to rise to
20C over 1.5 hours.
To the reaction mixture was added 2M hydrochloric acid (50 ml) with vigorous
stirring for 30 minutes and then the mixture was extracted with ether (150 ml). The
organic layer was separated, washed with water (100 ml) and dried over anhydrousm~gn~ei~lm sulphate. The mixture was filtered and the filtrate evaporated under
reduced pressure to yield a beige solid which, on recryst~llie~,tion from a minim~lm
volume of boiling water, afforded cream needles (5.50 g); mp > 300C.
Microanalysis: C7H6BNO2 % found ( calculated )
C 56.96 (57.21) H 4.14 (4.12) N 9.42 (9.53)
(b) 3-Bromo-4'-cyanobiphenyl
To a vigorously stirred solution of 1,3-dibromobenzene (26.49 g, Fluka) in toluene
(610 ml) under a nitrogen atmosphere, was added
tetrakis(triphenylphosphine)p~ m(O), (1.30 g, Aldrich). Once all the solid had
dissolved, a solution of the product from Example l(a) (5.50 g) in a minimllm
volume of ethanol was added, followed by a 2M aqueous solution of sodium
carbonate (41 ml). The vigorously stirred mixture was then heated under reflux for
19 hours with the exclusion of light.
The reaction mixture was cooled to room tenlpel~re, diluted with water (100 ml)
and the layers were separated. The aqueous layer was extracted with fresh toluene
(100 ml) and the organic layers were then combined, washed with water (2 x 250
ml), dried over anhydrous m~gneeil-m sulphate and filtered. Evaporation under
reduced pressure gave a yellow oil which was purified by silica gel column
chromatography, eluting firstly with petroleum ether bp 40-60C then with diethyl
ether/petroleum ether bp 40-60C (2:1) to give the pure product as a colourless
solid (4.50 g) together with some slightly impure product as a pale yellow solid
SUBSTITUTE SHEET (RULE 26~
WO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 19-
(2.44 g).
IR gave an intense peak at 2224 cm~l (CN stretch)
Mass Spectrometry (EI: (M+1)~ at 257 and 259
Microanalysis: C13HgBrN % found (calculated)
C 62.16 (60.49) H 3.22 (3.12) N 5.44 (5.43)
(c) (E)-N~O-Bis(t-butoxycarbonyl)-N-[3 -(4'-cyano-3-biphenylyl)- 1 (S)-methyl-2- propenyl]hydroxylamine
To a stirred solution of the product from Example 1(b) (4.50g) and N,O-bis(t-
butoxycarbonyl)-N-but-l-en-3(S)-ylhydroxylamine plepa~ed as described in EP
0384594 (Synthetic F.~ ,ple~ 2 and 3) (5.01g), in dry N,N-dul~,Lllylro~ ide
(17.5ml) and under a dry nitrogen atmosphere, was added triethylamine (3.91g,
Aldrich) followed by tri(o-tolyl)phosphine (215 mg, Aldrich) and p~ lm (II)
acetate (78 mg, T.:qnc.~ter). The stirred mixture was heated at 100C, with
exclusion of light, for 11 hours then cooled to room teul~ alL~re.
The reaction mixture was poured into water (250 ml) with stirring for 5 minutes,and then the mixture was extracted with ethyl acetate (3 x 100 ml). The extractswere combined, washed with water (3 x 150 ml), dried over anhydrous m~gnesillm
sulphate and filtered. The filtrate was evaporated under reduced pressure to give a
tan, viscous oil (7.66g) which was used without further purification.
(d) (E)-N-[3 -(4'-Cyano-3-biphenylyl)- 1 (S)-methyl-2-propenyl]hydroxylamine
A solution of crude product from Example 1(c) (7.66g) and toluene-4-sulphonic
acid monohydrate (4.14g, B.D.H.) in meth~nol (120 ml) was heated under gentle
reflux for 45 minutes then cooled to room telllp~l ~L~lre. The solution was
evaporated under reduced pressure and the residue treated with saturated aqueoussodium hydrogen carbonate solution (50ml) then extracted into ethyl acetate (3 x150 ~nl). The combined extracts were washed with water (2 x 150 ml), dried over
anhydrous m~nesillm sulphate and filtered. The filtrate was evaporated under
reduced pressure to give a tan gum (4.60g) which was used without further
purification
SU~STITUTE SH~ET (RULE 26)
WO 94/25431 21 6 1 5 4 4 PCT/GB94/00886
- 20 -
(e) (E)-O-Acetyl-N-[3 -(4'-cyano-3 -biphenylyl)- 1 (S)-methyl-2-propenyl]-
acetohydl o~,late
A stirred solution of crude product from Example l(d) (4.60g), pyridine (3.03g)and 4-(dimethylamino)pyridine (SOmg) in dichloromethane (lOOml) was cooled in
an ice bath with the exclusion of moisture. A solution of acetyl chloride (3.01g) in
dichloromethane (lOml) was added dropwise over 20 minutes, then stirring was
continued at 0C for 30 minutes then at room temperature for 16 hours.
The reaction mixture was evaporated under reduced pressure, the residue dissolved
in ethyl acetate (250ml) and the solution washed with 2M hydrochloric acid (2 x
lOOml) then with saturated aqueous sodium hydrogen carbonate solution (lOOml)
and finally with water (lOOml). The organic layer was dried over anhydrous
m~gn~eillm sulphate, filtered and the filtrate evaporated under reduced pressure to
give a tan gum. The product (2.26g) was isolated as a pale yellow gum by silica gel
column chromatography, eluting with diethyl ether.
(f) (E)-N-[3-(4'-Cyano-3-biphenylyl)-l(S)-methyl-2-p,~l)ellyl]acetohydroxamic acid
A solution of the product of Example l(e) (2.26g), in meth~nol (75ml) was cooledin an ice bath with the exclusion of moisture, then anhyd~oLls potassium carbonate
(1.79g) was added with stirring at 0C for 1 hour.
The reaction mixture was evaporated under reduced pressure and the residue
treated with water (lOOml) followed by acidification with citric acid. The mixture
was extracted with ethyl acetate (3 x lOOml) and the combined extracts were thenwashed with water (2 x 150ml) and dried over anhydrous m~gnesillm sulphate. The
mixture was filtered and the filtrate evaporated under reduced pressure to give a
pale orange gum from which the product (1.18g) was isolated as a pale yellow gumby silica gel column chrolllalography, eluting with diethyl ether. Trituration with
diethyl ether/petroleum ether bp 40-60C gave a solid which was then recrystallised
from ethyl acetate / ether (1:4) to give the product (0.94g) as a cream solid; mp
127-129C.
200 MH~ IH-N~ (DMSOd6) o: 9.5 (s, lH, OH), 8.0 - 7.4 (m, 8H, ArH), 6.7 -
SUBSTITUTE SHEET (RULE 26)
WO 94/25431 pcTlGs94loo886
21 61 544
- 21 -
6.3 ( m, 2H, vinyl-H), 5.3 - 5.1 (m, lH, methine-H), 2.05 (s, 3H, acetyl-H), 1.35
- 1.25 (d, 3H, methyl-H) .
rR gave intense peaks at 2222 cm~1 (CN stretch) and 1597 cm~1 (CO stretch)
[a]D=-149.16 [a]Hg546=-184.41 (c= 1.0, ethanol)
Microanalysis: C 1gH1 gN202 % found ( c~lc~ ted )
C 74.21 (74.49) H 5.90 (5,92) N 8.98 (9.15)
Synthetic Example 2
P, e~a, alion of (E)-N-r3 -(4'-fluoro-3-biphenylyl)- 1 (S)-methyl-2-propenyl]-acetohydrox~llic
acid
(a) 4-fluorophenylboronic acid
A stirred solution of 4-fluorobrolllobenzene (105g) in dry tetrahydrofuran (THF)(SOOml) under nitrogen was cooled to -70C and then a 1.6M solution of
butyllithium in hexane (375ml) was added slowly, keeping the temperature below -67
C. Stirring was then continued at -70C for 10 minutes before pumping the rnixture
gradually into a stirred mixture oftri(isopropyl)borate (277ml) and dry THF (lOOml)
under nitrogen at -70C. After the addition, the reaction mixture was stirred at -70
C for 10 minutes before being allowed to warm to ambient telll~ re. 2M
aqueous hydrochloric acid (300ml) was then added and the reaction was stirred for a
further 30 mimltes.
The reaction mixture was diluted with diethyl ether (125ml) and the resulting
aqueous layer was separated and washed with diethyl ether (2xl25ml). The
combined ethereal solutions were washed with water and dried over MgS04.
Removal of the solvent gave the title compound as a cream solid (78.5g).
(b) 3-Bromo-4'-fluorobiphenyl
To a stirred solution of 1,3-dibromobenzene (397g) in toluene (3.0 litres) undernitrogen, was added tetrakis (triphenylphosphine) p~ m (O) (16.5g). A solution
SU~ST~TlJT~ SH~T (RU~ 26)
WO 94/25431 '2 1 61 5 4 4 PCT/Gs94/00886
of the product from Exarnple 2(a) (78.5g) in absolute ethanol (500ml) was then
added followed by 2M aqueous Na2CO3 (561ml).
The vigorously stirred reaction mixture was then refluxed for 11 hours under
nitrogen. On cooling, the separated toluene layer was washed with water
(2 x 500ml) and dried over MgSO4. Distillation afforded the title compound (85-90
C/0. lmbar).
(c) N~O-Bis(t-butoxycarbonyl)-N-[3-(4'-fluoro-3-biphenylyl)-1(S)-methyl-2-propenyl]-
hydroxylamine
To a stirred mixture of the product from Example 2(b) (63.49g) and N,O-Bis(t-
butoxycarbonyl)-N-(but-3-en-2(S)-yl]hydroxylamine prepared as described in
EP 0384594 (Synthetic examples 2 and 3) (72.60g), and dly N,N-dimethylformamide
(DMF) (250ml) under nitrogen, was added triethylamine (56.66g), tri(o-
tolyl)phosphine (3.1 lg) and then p~ lm (II) acetate (1.14g). The stirred reaction
mixture was then heated at 100C for 9 hours.
On cooling, the reaction mixture was poured into water (2.5 litres), and extracted
with diethyl ether (4x500ml). The col"~ ed ether extracts were then washed with
water (3x500ml), dried over MgSO4, and treated with charcoal. Removal of the
solvent gave the title compound (110.2g).
(d) (E)-N-[3-(4'-fluoro-3-biphenylyl)-1(S)-methyl-2-propenyl]hydroxylamine
A solution of the product from Example 2(c) (0.253mol) in methanol (lOOOml) was
treated with toluene-4-sulphonic acid monohydrate (60.09g) and then refluxed for105mins.
The cooled reaction mixture was evaporated under reduced pressure, the residue was
treated with excess saturated aqueous NaHCO3 and extracted with diethyl ether
(3x300ml). The combined ether extracts were dried over MgSO4 before removing
the solvent under reduced pressure to give the title compound as a tan oil.
(e) (E)-N-[3-(4'-fluoro-3 -biphenylyl)- l (S)-methyl-2-propenyl]acetohydl o~alllic acid
SUBSTITU~E SHEET (RULE 26a
WO 94/25431 2 1 6 1 5 4 4 PcTlGs94loo886
A stirred solution of the product from Example 2(d) (43.97g) in dichlorometh~ne
(1000ml) was cooled to 0C with the exclusion of moisture. 4-dimethylaminopyridine
(l.Og) was added, followed by dropwise addition of acetyl chloride (41.71g).
Stirring was continued at 0C for 45 minutes then at room temperature for 14 hours.
The reaction mixture was evaporated under reduced pressure and the residue was
partitioned between diethyl ether (750ml) and 2M HCI (500ml). The separated
aqueous phase was washed with diethyl ether (750ml) and the combined ether
fractions washed s~lcces~ively with 2M HCI, saturated NaHCO3 and water before
dried on MgS04. Evaporation in vacuo followed by flash chromatography (SiO2,
diethyl ether/40-60C petroleum ether 2: 1) afforded the bis-acetyl compound.
Anhydrous K2CO3 (32.93g) was added to a solution of the bis-acetyl compound
(40.68g) in meth~nQI (600ml), cooling in an ice-bath. The reaction was stirred for
1 hour at 0C with the exclusion of moisture then evaporated in vacuo.
The residue was treated with water (500ml) then acidified with citric acid and
extracted with diethyl ether (3x300ml). The combined ether extracts were washed
with water (2x500ml) and dried over MgSO4. Removal of the solvent gave the
crude title product as an orange oil (37.36g). Purification by flash cl~olllatography
(SiO2, diethyl ether) and recryst~ tion from 40-60C Petroleum ether/diethyl ether
gave the title compound as a white fluffy solid, mp ?2-76C;
Microanalysis: ClgHlgFNO2. 0.6 H20 found (calculated) %:
C 69.77 (69.70), H 6.12 (6.24), N 4.55 (4.52);
Optical rotation (c=1.0, EtOH): [a]2D = -162.26, [a~2H 546 = 200.99.
(f) Anhydrous form of (E)-N-[3-(4'-Fluoro-3-biphenylyl)-l(S)-methyl-2-propenyl]
acetohydroxamic acid
The product from Example 2(e) (100 mg) was heated at 40C and 0.05 mbar for 1
hour. The telllpe~L~Ire was raised to 55C for a further 1 hour, then to 80OC for 3
hours. Heating was removed and the melt allowed to return to room te~lpe,~ re
before the vacuum was released. The colourless, glassy residue was triturated with
a 2:1 mixture of diethyl ether and petroleum ether bp 40-60C (5 ml) to yield a
SUBSTlTUTE SHEET (RULE 26~
~1 6l ~4
Wo 94/25431 pcTlGs94loo886
- 24 -
colourless, feathery, crystalline solid (70 mg); mp 115-117C.
200 MHz 1H-NMR (DMSOd6) o: 9.25 (s, lH, OH), 7.8 - 7.2 (m, 8E~ ArH),
6.7-6.3 (m, 2H, vinyl-H), 5.3 - 5.1 (m, lH, methine-H), 2.0 (s, 3H, acetyl-H), 1.4-
1.2 d, 3H, methyl-H).
FAB-Mass Spectrometry: (M+l)+ at 300, (M+Na)+ at 322
[a]D =-172.3, [a]Hg546= -213.5 (c=1.0, EtOH)
Microanalysis: C18H18FNO2% found ( calculated )
C 72.04 (72.22) H 6.04 (6.06) N 4.54 (4.68)
Synthetic Exarnple 3
Pl ep&l ~lion of (E)-N-[3 -(4'-Chloro-3-biphenylyl)- 1 (S)-methylprop-2-enyl]-
acetohydlox~,lic acid
(a) 3-Bromo-4'-chlorobiphenyl
4-Chlorobenzeneboronic acid (3.13g, 20mmol) was added to a solution co,,~ g
l-bromo-3-iodobenzene (5.66g 20 mmol) and tetrakis
(triphenylphosphine)p~ m(O) (250mg) in TH~ (60ml), under nitrogen.
Deoxygenated water (60ml) was then added, followed by sodium carbonate (4.24g,
40mmol). The rnixture was heated at reflux under nitrogen for 16 h. After cooling,
ether was added and the two phases separated. The organic phase was washed with
water and saturated brine, dried over sodium sulphate and the solvent removed.
The residue was taken up in hexane and filtered to remove some insoluble solid.
The hexane was evaporated and the product purified by chlol,la~ography on silica,
eluting with cyclohexane, to give 3-bromo-4'-chlorobiphenyl (3.63g, 68%) as a
colourless oil.
(b) (E)-N.O-Bis (t-butoxycarbonyl)-N-[3 -(4'-chloro-3 -biphenylyl)- 1 (S)-
methylprop-2-enyl]hydroxylamine and (E)-N-(t-butoxycarbonyl)-N-[3-(4'-chloro-3-
biphenylyl)- 1 (S)-methylprop-2-enyl] hydroxylamine
SU~STITUTE SHE~T (RULE 26
2 1 6 1 544
wO 94/2~431 pcTlGs94loo886
To the product from Example 3(a) (2.68g, 10mmol) and (S)-N,O-bis(t-
butoxycarbonyl)-N-but-3-en-2-ylhydroxylamine (3.16g, llmmol) in dry DMF
(40ml) was added triethylarnine (3.06ml, 22mmol) followed by tri(o-tolyl)phosphine
(304mg, lmmol) and finally p~ m acetate (112mg, 0.5mmol). The mixture was
heated, under N2, at 110-120C for 8 h. After cooling, the mixture was poured
into water and extracted with ethyl acetate. The extracts were washed with water(3x), then with saturated brine, dried (Na2SO4) and the solvent evaporated, giving
a brown gum. The residue showed two major components on TLC, Rf 15 0.43 and
0.22 (EtOAc-cyclohexane, 1:4). They were sep~ed by column cllrol,latography,
eluting with ethylacetate-cyclohexane, (1:6). The first eluted compound (1.64g)
was the N,O-bis(t-butoxycarbonyl) product and the slower-running component
(1.74g) was the N-mono(t-butoxycarbonyl) compound. Both compounds were
gums, co~ g impurities by NMR and were combined and used directly.in the
following step.
(c) (E)-N-[3-(4'-Chloro-3-biphenylyl)- 1 (S)-methylprop-2-enyl]hydroxylamine
The combined mono- and bis-(t-butoxycarbonyl) compounds from the previous
reaction (total of 3.34g) were dissolved in toluene (50ml) and p-tol-l~nes~llphonic
acid (1.52g, 9mmol) added. The mixture was stirred and heated at 55-60C for 3h.After cooling, it was washed with aqueous sodium bicarbonate, then with saturated
brine. Drying (Na2SO4) followed by solvent removal gave a gum which was
purified by chrollla~ography on silica, eluting with dichlorometh~ne-meth~nQI
(20:1). The pure hydroxylamine was obtained as a pale yellow oil which slowly
solidified (0.86g).
(d) (E)-N~O-bis(acetyl)-N-~3 -(4'-chloro-3 -biphenylyl)- 1 (S)-methyl prop-2-enyl]-
hydroxylamine
The product from Example 3(e) (0.84g, 3.07mmol) in dichlo~olll~lhane (25ml) was
stirred at OC under dry N2 as pyridine (0.57rnl, 7mrnol) was added, followed byacetyl chloride (0.50ml, 7rnmol), added dropwise. The rnixture was stirred for 16h,
allowing to slowly warm to room temperature. The rnixture was washed with water
and saturated brine, dried (Na2S04) and the solvent evaporated. Purification wasachieved by chloll-a~ography on silica (ethyl acetate-cyclohexane, 1:2), giving the
SUBSTITUTE SHEET (RULE 261
WO 94/25431 PCT/GB94/00886
21 61 544
required product as a colourless gum (0.95g, 86%).
(e) (E)-N-[3 -(4'-Chloro-3-biphenylyl)- 1 (S)-llleLllyll)rop-2-enyl]acetohydl o~alllic acid
The product from Example 3(d) (0.93g, 2.60mmol) was stirred in meth~nol (25ml)
at OC. Potassium carbonate (414mg, 3mmol) was added, and the mixture stirred
for 4h. The solvent was evaporated and the residue partitioned between ethyl
acetate and lM HCI. The organic layer was separated, washed with water (2x),
then saturated brine, dried (Na2S04) and the solvent evaporated, giving, initially, a
gum, which crystallised upon dissolution in ether and scratching. The pure
hydroxamic acid was filtered off, washed with ether and dried (0.63g 77%). mp.
lO9-111C. MS M/z 315,317 (M+)
Microanalysis: Calcd: C, 68.46; H, 5.75, N, 4.44%
Found: C, 68.33; H, 5.67; N, 4.37%.
Synthetic Example 4
(a) 3-(4'-Fluorophenyl)b~n7~1clçhyde
To a solution of the product from Example 2(b) (5.0g) in THF (50ml), under
nitrogen, was added n-butyl lithium (1.6M solution in hexane, 12.5ml), m~int~ining a
telllpe~ re of around -70C. DMF (1.55ml) was then added slowly keeping the
telllpel~ re in the range -73 to -53C.
After warming to room temperature, saturated ammonium chloride solution (150ml)
was added and the mixture was extracted with diethyl ether (3 x 50ml). The
combined ethereal extracts were washed with water then dried over MgSO4, filtered,
and concentrated in vacuo to give the product as a pale yellow oil.
(b) (E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-one
A mixture of the product from Example 4(a) (4.0g), dimethyl-(2-oxopropyl)
phosphonate (2.76ml), anhydrous potassium carbonate (5.5g) in THF (60ml) was
stirred at around 60C under nitrogen until reaction was complete. The reaction
mixture was filtered, concentrated, then purified by column chromatography on
SUBS~I~U~E SHE~T (~ULE 26~
2161~44
wo 94/25431 PCT/GB94100886
silica, eluting with ethyl acetate/hexane to afford the crude title compound.
Recryst~ tion from ethyl acetate/hexane gave the product as a white crystalline
solid, mp 67-68C.
Microanalysis: C 79.77 (79.98), H 5.48 (5.45)
(c) (E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-(S)-ol
To a solution of the product from Example 4(b) (0.5g) and butyl diphenyl CBS
catalyst (0.066g) in toluene (20ml), under an atmosphere of nitrogen, was added
catechol borane (lM solution in toluene, 4.16rnl) ensuring that the internal
te~ e~ re was kept below - 55C. Upon complete addition the resulting yellow
solution was stirred at -55C for 18 hours.
After warming to room tenli)el~ re, 40% sodium hydroxide solution (20ml) and
diethyl ether (50ml) were added and the mixture washed with 40% sodium hydroxidesolution (3xlOml) and water (15ml). The combined organics were dried over
MgS04, filtered, and concentrated in vacuo to give the product as a viscous oil
(0.38g) which rapidly solidified. The product was determined to have an 80%
enantiomeric excess by chiral HPLC methodology.
(d) ~E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-(S)-ol (Alternative method)
Under an atmosphere of nitrogen, to a stirred and cooled (ca. 0C) suspension of the
product from Example 4(b) (lOg, 0.0416mol) in SVM (95% ethanoV 5% meth~nol)
(lOOml) was added sodium borohydride (1.56g, 0.041mol) portionwise. The
reaction was stirred at 0C for 2 hours and then q~lenched into water (300ml).
SVM was removed in vac7uo and the aqueous residue was extracted with diethyl
ether (3.75ml). The combined ether exctracts were washed with water (2.100ml),
brine (lOOml) and dried over magnesium sulphate. The solution was concentrated to
a pale yellow oil (10.66g) which solidified on st~ntling Cryst~llis~tion from diethyl
ether/hexane yielded (E)-4-(4'-fluoro-3-biphenylyl)-3-buten-2-ol as a white
crystalline solid (8.12g, 80% yield). Melting point = 53-54C.
The racemic alcohol (3g, 0.0124mol), toluene (30ml), vinyl acetate (5.33g,
SUBSrlTUTE SHEET (RULE 26~
WO 94/25431 21 6 1 5 4 ~ PCT/Gs94/00886
- 28 -
0.0619mol) and Amano lipase PS (0.3g, from Pseudomonas fluorescens) were
stirred together at room telllpcl a~l~re for 72 hours. The reaction was filtered through
Hyflo and concentrated to a yellow oil. Column cl.~ollla~ography was used to
separate the title product from the corresponding O-acetylated (R) enantiomer.
(E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-(S)-ol was obtained as a white solid (1.39g,
46.3% yield) Mpt = 52-53C, with a 99.6% enantiomeric excess.
Microanalysis C 78.95 (79.31), H 6.35 (6.24), F 7.97 (7.84).
3-(R)-O-Acetoxyl-1-(3',4-fluorobiphellylyl)-but-2-ene was obtained as a yellow oil
(1.63g, 46.2% yield), with a 99.9% enantiomeric excess.
Microanalysis C 75.87 (76.03), H 5.92 (6.03), F 6.86 (6.63).
(e) (E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-(R)-ol
A solution of the O-acetylated product from Example 4(d) (25g) in methanol
(120ml) and 40% sodium hydroxide solution (30ml) was cooled at 0C and stirred
for 90 minutes. Methanol was removed in vacuo and the residue partitioned between
diethyl ether and water. The resulting aqueous layer was extracted with diethyl ether
(3.150ml) and the combined extracts were washed water water (2xlOOml), and brine(lOOml). The solvent was dried over m~eil~m sulphate and the solvent removed
in vacuo to leave a pale oil (19.42g). The oil was crystalised from diethyl
ether/hexane to give a white solid. The product alcohol was determined to have a97.1% enantiomeric excess by chiral HPLC methodology.
(f) ~c~mis~tion of (E)-4-(4'-Fluoro-3-biphenylyl)-3-buten-2-(R)-ol
.
A solution of the alcohol product from Example 4(e) (49. lg) in TH~ (lOOOml) and2N hydrochloric acid (500ml) was stired at room telllpel~-re for 72 hours. The
reaction mixture was diluted with water (lOOOml) and diethyl ether (lOOOml) and the
resulting aqueous layer extracted with diethyl ether (500ml). The colllbil~ed organic
layer was washed with water (500ml) and dried over m~n~ei~lm sulphate. The
solvent was removed in vacuo to leave a yellow oil (51.2g). The oil was determined
to be a racemic mixture by chiral HPLC methodology. This material can then be
'recycled' by using it in the process described in Example 4(d).
SUBSTITUTE SHEET (RULE 26~
WO 94/25431 2 1 6 1 5 4 4 PCT/GB94/00886
- 29 -
(g) 3 -(S!-O-(chloroacetoxy)- 1 -(3 '~4-fluorobiphenylyl)-but-2-ene
A solution of the product from Example 4(d) (0.5g), pyridine (0.31ml), and 4-
dimethylaminopyridine (ca. lmg) in THF (lOml) was cooled to 0C under an
atmosphere of nitrogen. A solution of chloroacetyl chloride (0.19ml) in THF (5ml)
was added dropwise to the solution at such a rate as to IIIA;1l~ the te~ lal~re at
0C. The resulting solution was stirred at ca. O to -4C for 18 hours.
The reaction mixture was allowed to warm to room temperature and was diluted
with water (50ml). The resulting organic phase was washed with water (50ml)
diluted with toluene (50ml) and solvent removed under reduced pressure to leave a
colourless oil. This oil was purified by column chroll,alography to give the product
as a viscous colourless oil (0.49g).
(h) O-(tetrahydropyran-2-yl)-N-[1 -(4'-fluoro-3 -biphenylyl)but- 1 -en-3 -(S)-yl] -
hydroxylamine
Bis[dibenzylid~ne~cetone] pAllA~illm (0.181g), lithium chloride (0.013g) and
triphenylphosphine (0.165g) were dissolved in deg~sed, peroxide free TH~/DMF
(l:lv/v, 60ml) under an atmosphere of dry nitrogen. The mixture was stirred at
70C for 45 minutes before a solution of the product from Example 4(g) (5g) in
THF/DMF (l:lv/v, lOml) under an atmosphere of nitrogen, was added dropwise.
The resulting mixture was stirred at 70C for 1 hour before a solution of
O-tetraLydlopyl~l-2-ylhydroxylamine (3.67g) in THF/DMF (l:lv/v, lOml) under an
atmosphere of nitrogen, was added dropwise. The reaction mixture was stirred at
70C for 48 hours.
The mixture was diluted with diethyl ether (50ml) and water (50ml) and the aqueous
layer extracted with diethyl ether (50ml). The combined organic layers were washed
with water (50ml), dried over m~gnesium sulphate, and concellLI~led to leave a
yellow oil (5.6g). The oil was purified by column chromatography to give the
product as a viscous colourless oil (2.86g).
(i) O-(tetrahydropyran-2-yl) N-acetyLN-{ 1-(4'-fluoro-3-biphenylyl)but-1-en-3-(S)-yl]
hydroxylamine
SUBSTITUTE SHEET ~RULE 26)
wO 94/25431 2 1 61 5 4 4 PCT/GB94/00886
- 30 -
To a solution of the product from Example 4(h) (1.95g) in dry triethylamine (20ml)
at 0C was added a solution of acetyl chloride (0.8g) in dichlorometh~ne (20ml),ensuring that the temperature did not rise above 0C. The mixture was warmed to
room temperature over 14 hours and the reaction mixture was poured into water
(SOml). The aqueous phase was extracted with ethyl acetate (4 x 50ml) and the
combined organic extracts were dried over m~gn~sillm sulphate and concentrated to
give the product as a gum (2. lg).
(j) (E)-N-[3 -(4'-fluoro-3 -biphenylyl)- 1 (S)-methyl-prop-2-enyl]acetohydl oxalllic acid
To a solution of the product from Example 4(i) (1.9Og) in absolute ethanol (lOOml)
was added Amberlyst H15 (2.0g). The mixture was stirred at room temperature for
48 hours and the Amberlyst H15 was removed by filtration, the filtrate was treated
with anhydrous potassium carbonate (0.2g) and the resulting mixture was
concentrated under reduced pressure to leave an oily residue. Water (50ml) was
added and the aqueous layer was extracted with ethyl acetate (4 x 50ml). The
combined extracts were dried over m~gnesi~lm sulphate and concentrated to leave an
oily residue. The residue was cryst~ ed from diethyl ether/petroleum ether (60-80)
after column chrc,l,la~ography to give the product as a white solid (0.25g).
Synthetic Example 5
Pl ep~ ~Lion of (S)-(E)-N-2-[4-(4'-Fluoro-3-biphenylyl)-but-3-enyl]-0-(ethoxycarbonyl-
methylaminocarbonyl) acetohydr-~x~llic acid
The product from Example 2(e) (0.299g, lmmol) was dissolved in dry THF (5ml)
under nitrogen and N-methylmorpholine (0.202g, 0.220ml, 2mmol) was added in
one portion, followed by ethyl isocy~n~toacet~te (0.129g, 0.112ml, lmmol). The
mixture was stirred at room temperature overnight, then was partitioned between
ethyl acetate and lN hydrochloric acid. The organic phase was separated, washed
with saturated brine, dried over anhydrous sodium sulphate, filtered and evaporated
in vacuo. Chromatographic purification of the crude produce on silica, with 1:1
ethyl acetate:cyclohexane eluent gave the title compound (0.257g, 52%) as a waxysolid.
N.m.r. spectrum (200MHz in DMSO-d6) o: 1.16 (3H,t), 1.33 (3H,d), 2.01 (3H, s),
SU~STITUTE SHE~T ~RUl 26~
WO 94125431 PCT/GB94/00886
-31 2 1 6 1 544
3.81 (2H, d), 4.07 (2H, m), 5.23 (lH, m), 6.32-6.68 (2H, m), 7.22-7.79 (8H, m),
8.35 (lH, t).
PHARMACEUTICAL FORMULATION EXAMPLES
The "active ingredient" in the following formulations is as defined above; preferably one of
the compounds of Synthetic Examples 1 to 4.
Example A: Oral Tablet (i)
Per tablet
Active Ingredient 50.0 mg
Lactose 61.0 mg
Sodium Starch Glycollate - 10.0 mg
Povidone 3.0 mg
Magnesium Stearate 1.0 mg
Mix together the active ingredient, lactose and sodium starch glycollate . Granulate the
powders using a solution of povidone in purified water. Dry the granules, add the
magnesium stearate and COlllpl~SS to produce tablets.
Example B: Ointment
Active Ingredient 1.0 g
White Soft Paraffin to 100.0 g
Disperse the active ingredient in a small volume of the vehicle. Gradually incorporate this
into the bulk to produce a smooth, homogeneous product. Fill into collapsible metal tubes.
Example C: Cream for topical use
Active Ingredient 1.0 g
Polawax GP 200 20.0 g
Lanolin Anhydrous 2.0 g
White Beeswax 2.5 g
Methyl hydroxybenzoate 0.1 g
Distilled Water to 100.0 g
SUBSTITUTE SHEET (RULE 26)
WO 94/25431 2 1 6 1 5 4 4 32 - PCT/Gs94/00886
Heat the Polawax, beeswax and lanolin together at 60C. Add a solution of methylhydroxyl,enzoale. Homog~ni~e using high speed stirring. Allow the temperature to fall to
50C. Add and disperse the active ing.t;diell~. Allow to cool with slow speed stirring.
Example D: Lotion for topical use
Active Ingredient 1.0 g
Sorbitan Monolaurate 0.6 g
Polysorbate 20 0.6 g
Cetostearyl Alcohol 1.2 g
Glycerin 6.0 g
Methyl Hydroxybenzoate 0.2 g
Purified Water B.P. to100 ml
The methyl hydroxybenzoate and glycerin were dissolved in 70ml of the water at 75C.
The sorbitan monolaurate, Polysorbate 20 and cetostearyl alcohol were melted together at
75C and added to the aqueous solution. The resulting emulsion was homog~ni~e~,
allowed to cool with continuous stirring and the active ingredient added as a suspension in
the Ir~ ing water. The whole was stirred until homogeneous.
Example E: Oral Tablet (ii)
Per tablet
Active Ingredient 10.0 mg
Lactose 80.0 mg
Microcrystalline Cellulose 40.0 mg
Povidone 4.0 mg
Sodium Starch Glycollate 15.0 mg
~yn-o.cillm Stearate 1.0 mg
Mix together the active ingredient and microcrystalline cellulose before blending with
lactose, povidone and sodium starch glycollate. Lubricate with m~gn~.cil.m stearate and
compress to produce tablets ( 1 50mg per tablet).
SUBST~TUTE SHEET ~RULE 26)
WO 94/25431 2 1 5 1 5 4 4 pcTlGs94loo886
- 33 -
Example F: Oral capsule
Active Ingredient 25.0 mg
Starch 1500 100.0 mg
Sodium Starch Glycollate 14.0 mg
~f~ne~ m Stearate 1.0 mg
Mix to,~ether the active ingredient, Starch 1500 and sodium starch glycollate before
blending with mAgnesillm stearate. Fill power into Size 3 capsule shells (140 mg per
capsule).
Example G: Powder capsules for inhalation
Active Ingredient (0.5-7.0~m powder) 1.0 mg
Lactose (30-90,um powder) 49.0 mg
The powders were mixed until homogeneous and filled into suitably sized hard gelatin
capsules (50mg per capsule).
Example H: Inhalation aerosol
Active Ingredient (0.5-7.0~m powder) 50.0 mg
Sorbitan Trioleate 100.0 mg
Saccharin Sodium (0.5-7.0~1m powder) 5.0 mg
Methanol 2.0 mg
Trichlorofluolo",~lh~lle 4.2 g
DichlorodifluoromethAne to 10.0 ml
The sorbitan trioleate and menthol were dissolved in the trichloro-fluoro,,,~ll,AI~e. The
saccharin sodium and active ingredient were dispersed in the mixture which was then
sre-led to a suitable aerosol canister and the dichlorofluoromethane injected through
the valve system. This composition provides 0.5mg of active ingredient in each 100~11
dose.
SUBST~TUT~ SHEET (RULE 26)
WO 94/25431 PCT/GB94/00886
~1 61 544 34
BIOLOGICAL DATA
In vitro inhibition of 5-lipoxy~enase
Leukocytes were isolated from blood donated by normal aspirin-free volunteers by washing
and centrifugation. A solution of the test compound in DMSO (10~1 final concentration
0.01 - lOO~M) was added to the washed cell suspension (480~1) and the mixture incubated
at room te~ )e~lure for 5 rninutes. The tubes were placed on ice for 5 minutes and then
stim~ ted with the calcium ionophore A-23187 (10~1, final conce"l~ion 2.0~M) for 5
minutes at 37C. The reaction was terminated by boiling and the plasma concentration of
LTB4 determined by Scintillation P,o~"-,ly Assay (SPA)
Each of the compounds of Synthetic Examples 1 to 4 when tested in this screen wa s found
to have an average ICso of less than 1 ~lM.
In Yitro inhibition of cyclooxygenase
Washed platelet suspensions from healthy human donors were prepared according to the
method of Radomski et al (Thromb. Res., 30 383-393 1983). Tubes cont~ining aliquots
(0.5ml) of platelet suspension (107 cells/ml) were incubated with test drug or vehicle for 5
minutes at room temperature before being placed on an ice bath for a further 5 minutes.
The calcium ionophore A-23187 was added (final concentration 211M) and the tubes were
incubated for 5 minutes at 37C. The reaction was termin~ted by boiling for 2 minutes and
the cellular prec.ipit~te removed ffir centrifugation. The thromboxane B2 content of the
supe~"ata~ll was determined by radio-immunoassay.
Each of the compounds of Synthetic Examples 1 to 4 when tested in this screen was found
to have an average ICso of less than 10~1M.
SU~ST5TUTE SHEET IRULE 26
