Note: Descriptions are shown in the official language in which they were submitted.
2~5~9~6
The invention relates to 2~,3~-dideoxy-5-trifluoromethyl-
uridines, processes for their preparation and their use
as medicaments, in particular as medicaments against
hepatitis.
About 300 million people worldwide are sick with hepa-
titis B, about l million new illnesses being recorded
each year in the USA and Europe alone. ;r
It is known that certain 2',3'-dideoxynucleosides which
are unsubstituted in the 2'- and 3'-position act against
hepatitis (B) viruses [cf. U.S. Pat. Appl. 351 502
(15.8.89); EP 302 760]. 21,3~-Dideoxy-cytidine (DDC) is
explicitly described in WO 90/14,079 as a medicament
against hepatitis B. It is additionally known by means of
the publication tD.L.J. Tyrell et al., Biochem. Biophys.
Res. Commun. 156, 1144 - 1148 (1988)] that only 2',3'-di-
deoxypurine nucleosides, but not 2',3'-dideoxypyrimidine
nucleosides, exhibit an activity against DHBV (duck
hepatitis B virus). It is additlonally indicated that in
EP 217,580 the only correct starting compound for the
process there, 2'-dideoxy-5-trifluoromethyluridine, was
erroneously published with the wrong nomenclature -
2',3'-dideoxy-5-trifluoromethyluridine - (Example 34) and
thus also accepted by Chemical Abstracts under
RN 108,441/81/2 a~ the qtructure, without this compound
havinq previously been included by the scope of meaning
of a published application or of a patent or mentioned as
Le A 28 306 - 1 -
ZC6~916
23189-7323
an actual representative substance.
The invention relates to 2~,3~-dideoxy-5-trifluoromethyl-
uridines of the general formula (I)
O
HN ~ CF3
RlO O ~ N ~ (I)
~ ~ .
in which
Rl represents hydrogen or a hydroxyl protective group,
benzoyl, 4-methylbenzoyl or a straight-chain or
branched acyl having up to 18 carbon atom~, which i8
optionally substituted by carboxyl,
represents an amino acid which is optionally sub~ti-
tuted by an amino protective group customary in
peptide chemistry,
representa an ether radical which can be cleaved in
vivo, or
represents ~ radical of the formulae
Le A 28 306 - 2 -
2~5~9~ ~
23189-7323
HO-P - HO - P ~ o- p _~ HO-P -
oR2 OR~ oR4)~ R5
in which
R2, R3 and R4 are identical or different and denote
hydrogen or an alkali metal or alkaline earth
metal atom,
n denote~ the number 1 or 2,
R5 denotes straight-chain or branched alkyl having
up to 6 carbon atoms, which is optionally substi-
tuted by halogen,
and their physiologically acceptable salts.
In the context of the present invention, physiologically
acceptable salts are preferred. Physiologically accept-
able ~alts of the compounds according to the invention
can be salts of the substancee according to the invention
with mineral acid~, carboxylic acid~ or sulphonic acids.
Particularly preferred salts are, for example, those with
hydrochloric acid, hydrobromic acid, sulphuric acid,
phosphoric acid, methanesulphonic acid, ethanesulphonic
acid, toluenesulphonic acid, benzenesulphonic acid,
Le A 28 306 - 3 -
-
9~6
naphthalenedisulphonic acid, acetic acid, propionic acid,
lactic acid, tartaric acid, citric acid, fumaric acid,
maleic acid or benzoic acid.
Salts which can be mentioned are also salts with custom-
ary bases, such as, for example, alkali metal salts (for
example sodium or potassium salts), alkaline earth metal
salts (for example calcium Gr magnesium salts) or am-
monium salts derived from ammonia or organic amines such
as, for example, diethylamine, triethylamine, ethyl-
dii~opropylamine, procaine, N-methylmorpholine or N-
methylpiperidine or dihydroabietylamine.
The compounds according to the invention can exist in
stereoisomeric forms, which either behave as image and
mirror image (enantiomers) or which do not behave as
image and mirror image (diastereomers). The invention
relates both to the antipodes and the racemic forms and
also the diastereomer mixtures. The racemic forms, like
the diastereomers, can be separated in a known manner
into the stereoisomerically uniform constituents [cf.
E.~. Eliel, Stereochemistry of Carbon Compounds, McGraw
H111, 1962].
Le A 28 306 - 4 -
23189-7323
o o
HN J~, ~ NH
a ) O~ N b) N ~O
R ~-O ~ ~ORl
D, ~ or (S,R) L, ~ or (R,S)
Hl.b3~
D, ~ or (S,S) L, ~ or (R,R)
Amino proteetive groupc in the context of the invention
are the euctomary amino proteetive groupc used in peptide
chemictry.
~hese preferably ineludes benzyloxycarbonyl, 3,4-dimeth-
oxybenzyloxyearbonyl, 3,5-dimethoxybenzyloxycarbonyl,
2,4-dimethoxybenzyloxycarbonyl, 4-methoxybenzyloxycar-
bonyl, 4-nitrobenzyloxycarbonyl, 2-nitrobenzyloxycar-
bonyl, 2-nitro-4,5-dimethoxybenzyloxycarbonyl, methoxy-
carbonyl, ethoxycarbonyl, propoxyearbonyl, i~OpropoxyCAr-
Le A 28 306 - 5 -
2Q649~6
bonyl, butoxycarbonyl, isobutoxycarbonyl, tert-butoxycar-
bonyl, allyloxycarbonyl, vinyloxycarbonyl, 2-nitrobenzyl-
oxycarbonyl, 3,4,5-trimethoxybenzyloxycarbonyl, cyclo-
hexylcarbor.yl, 1,1-dimethylethoxycarbonyl, adamantyl-
carbonyl, phthaloyl, 2,2,2-trichloroethoxycarbonyl,
2,2,2-trichloro-tert-butoxycarbonyl, menthyloxycarbonyl,
phenoxycarbonyl, 4-nitrophenoxycarbonyl, fluorenyl-9-
methoxycarbonyl, formyl, acetyl, propionyl, pivaloyl, 2-
chloroacetyl, 2-bromoacetyl, 2,2,2-trifluoroacetyl,
2,2,2-trichloroacetyl, benzoyl, 4-chlorobenzoyl, 4-bromo-
benzoyl, 4-nitrobenzoyl, phthalimido, isovaleroyl or
benzyloxymethylene, 4-nitrobenzyl, 2,4-dinitrobenzyl,
4-nitrophenyl.
Amino acids (-NH-CHR-C0-) in the context of the abovemen-
tioned definition (R1) in general represent the natural
amino acids from the series comprising alanine, aspara-
gine, a~partic acid, glutamic acid, glutamine, histidine,
leucine, methionine, proline, threonine, tyrosine,
arginine, cysteine, glycine, isoleucine, lysine, phenyl-
alanine, serine, tryptophan or valine, the linkage to theoxygen (R~-0-) in the general formula (I) taking place
via the carbonyl group while the terminal amino group i8
either pre~ent a~ a free NH2 group or optionally substi-
tuted by one of the abovementioned protective groups.
Hydroxyl protective group in the context of the abovemen-
tioned definition in general represents a protective
group from the series comprising: trimethylsilyl, tri-
ethylsilyl, triisopropylsilyl, tert-butyl-dimethylsilyl,
Le A 28 306 - 6 -
Z~5~ 23189-7323
ter~-butyldiphenylsilyl, triphenylsilyl, trLmethylsilyl-
ethoxycarbonyl, benzyl, triphenylmethyl(trityl), mono-
methoxytrityl (MMTr), dimethoxytrityl (DMTr), benzyloxy-
carbonyl, 2-nitrobenzyl, 4-nitrobenzyl, 2-nitrobenzyloxy-
carbonyl, 4-nitrobenzyloxycarbonyl, tert-butyloxy-
carbonyl, allyloxycarbonyl, 4-methoxybenzyl, 4-methoxy-
benzyloxycarbonyl, formyl, acetyl, trichloxoacetyl,
2,2,2-trichloroethoxycarbonyl, 2,4-dimethoxybenzyl, 2,4-
dimethoxybenzyloxycarbonyl, methoxymethyl, methyl-
thiomethyl, methoxyethoxymethyl, [2-(trimethyl-
silyl)ethoxy]methyl, 2-(methylthiomethoxy)ethoxycarbonyl,
tetrahydropyranyl, benzoyl, 4-methylbenzoyl, 4-nitro-
benzoyl, 4-fluorobenzoyl, 4-chlorobenzoyl or
4-methoxybenzoyl.
lS Ether radicals which can easily be eliminated in vivo in
the context of the abovementioned definition R1 represent
pharmaceutically tolerable ether radicals which can
easily be eliminated in vivo with liberation of the
OH group (R = H). Examples of such groups are disclosed
in EP 357,495.
Preferred ether groups which can be cleaved in vivo are
thoae of the following formulaes
(CH3)3C-CO-O-CH2- , CH3-CO-O-CH-CH3
CH3-CH20-CO-O-CH-CH3
Le A 28 306 - 7 -
Z ~ ~ ~ 9~ ~ 23189-7323
Depending on the particular meaning of the radical Rl,
the compounds of the general formula (I) according to the
invention can function as prodrugs, i.e. as pharmaceutic-
ally tolerable compounds which, on or after administra-
tion, if appropriate due to improved pharmacological and
pharmacokinetic behaviour, provide further compounds of
the general formula (I) which can be used according to
the invention and in which, for example, R1 = ~, as
metabolic products or degradation products [cf. for this
J. Pharm. Sci. 79, 531 (1990); EP 357,495; EP 362,967;
EP 366,386 and WP 90/04,969].
Preferred compounds of the general formula (I) are those
in which
R1 repre~ents hydrogen, tert-butyldimethylsilyl,
trimethyl~ilyl, triphenylmethyl, benzoyl, 4-methyl-
benzoyl or acetyl, or
represent~ straight-chain or branched acyl having up
to 16 carbon atom~, which is optionally substituted
by carboxyl, or
repre~ent~ leucine (Leu), valine (Val), i~o-
leucine ~Ile), phenylalanine (Phe), aspartic
acid (A~p) or glutamic acid ~Glu), which are option-
ally ~ub~tituted on the NH function by tert-butoxy-
carbonyl ~oc) or benzyloxycarbonyl ~Z), or
represents an e~her radical which can easily be
cleaved in vivo, of the formulae
Le A 28 306 - 8 -
2~9P~i
23189-7323
(CH3)3C-CO-O-CH2- , CH3-CO-O-CH-CH3
CH3-CH20-CO-O-CH-CH3
or
represents a radical of the formulae
O O O O
HO-P - HO - P - ................... HO-P -
oR2 oR31 OR~ n
in which
R2, R3 and R4 are identical or different and denote
hydrogen or a sodium metal atom,
n denote~ the number 1 or 2,
R5 denotes straight-chain or branched alkyl having
up to 4 carbon atoms, which i8 optionally substi-
tuted by chlorine,
and their physiologically acceptable salts.
Particularly preferred compounds of the general
Le A 28 306 - 9 -
ZQ~9~ 6 2318~-7323
formula (I) are those
ih which
R1 represents hydrogen, tert-butyldimethylsilyl, 4-
methylbenzoyl or benzoyl, or
represents straight-chain or branched acyl having up
to 14 carbon atoms, which is optionally substituted
by ~arboxyl, or
repre3ents leucine (Leu) or aspartic acid (Asp),
which are optionally substituted on the -NH function
by the protective group ~oc, or
represents an ether radical which can easily be
cleaved in vivo, of the formulae
(CH3)3C-CO-O-CH2- , CH3-CO-O-CH-CH3
CH3-CH20-CO-O-CH-CH3
or
represents a radical of the formulae
OR ~ ~ n
Le A 28 306 . - 10 -
2C~9~6
in which
R2, R3 and R4 are identical or different and denote
hydrogen or a sodium metal atom,
n denotes the number 1 or 2,
R5 denotes methyl, ethyl or chloromethyl,
and their physiologically acceptable salts.
Processes for the preparation of the compounds of the
general formula (I) according to the invention were
additionally found, characterised in that
[A] either 5-trifluoromethyluracil of the formula (II)
HN ~ CF3 ~II)
O NH
or
compounds of the general formula (III)
Le A 28 306 - 11 -
ZQ~9~6 23189-7323
oR6
~ CF3 ( III )
R6O N
in which
R6 represents one of the abovementioned silylhydroxyl
protective groups, preferably trimethylsilyl,
are first reacted with compounds of the general
formula (IV)
R7
~ (IV~
in which
R7 repre~ents one of the abovementioned hydroxyl
protective groups,
represents a typical leaving group such a~
acetoxy, bromine, chlorine, iodine, azido,
4-nitrophenoxy, bro~ylate, to~ylate, me~ylate,
Le A 28 306 - 12 -
-
Z~9~6 23189-7323
trifluoromethanesulphonate or fluorosulphonate,
preferably bromine, chlorine or acetoxy,
in inert solvents, if appropriate in the presence of a
base and/or of an auxiliary, to give compounds of the
general formula (Ia)
~ CF3
R70 0 ~ N (Ia)
in which
R7 has the abovementioned`meaning,
and which are either present a~ an ~ isomer mixture or
as ~- and ~-isomers,
or
[B] either the compounds of the general formula (III) are
reacted with the compounds of the general formula (IVa)
Le A 28 306 - 13 -
2 ~ 9~6 23189-73~3
R70 ~ (IVa~
R70 oR7
in which
R7 and T have the abovementioned meaning,
or
1~ D-ribofurano~yl)-5-trifluoromethyl-uracil of the
formula (V)
~ CF3
HO O ~ N ~ (V)
HO OH
is reacted with compounds of the general formula (VI)
R7-W (VI)
Le A 28 306 - 14 -
z~9~ 23189-7323
in which
R7 has the abovementioned meaning
and
W has the abovementioned meaning of T and is identical
to or different from this,
in inert solvents, if appropriate in the presence of a
base and/or of an auxiliary, and in the case of the
compound of the formula (V) with simultaneous blocking of
the vic-hydroxyl functions and/or of the primary hydroxyl
function, and subsequent liberation of the vic-hydroxyl
functions to give the compounds of the general
formula (VII)
~ CF3
HN
R70 N (VII
~0~
HO OH
in which
R7 ha~ the abovementioned meaning,
Le A 2~ 306 - 15 -
.
.
' ' ' ' ~ ' .
.
2C!6~9~6
and in a next step, by reaction with l,l'-thiocarbonyl-
diimidazole or dimethyl orthoformate, the~e are converted
into the corresponding 1,4-acetals or 1,3-thiocarbonates
of the general formula (VIII)
O
HN ~ CF3
~ i
R80 N
~ (VIII)
OyO
in which
R~ has the abovementioned meaning of R7 or represents
hydrogen
and
X represents a radical of the formula =S or -OCH3,
in inert solvents, in the presence of reducing agents and
if appropriate of a cst~lyst,
and in the case where R8 represents hydrogen, in one step,
by reaction with acetic anhydride, the primary hydroxyl
functioni~firstblocked, theacetal radical is elimina~ed
Le A 28 306 - 16 -
23189-7323
Z~ 9~6
with formation of a double bond and the latter is then
hydrogenated by customary methods,
and in the case where X represents the radical of the
formula =S, then reacted with trialkyl phosphites, such
as trimethyl, triethyl or tripropyl phosphite, preferably
with triethyl phosphite,
and in the case of the elimination of the 1,3-thio-
carbonate radical, first reduced in the presence of
reducing agents and of a catalyst, the reaction with
l,l'-thiocarbonyldiimidazole is repeated, and reduction
is finally carried out again,
or
[C] compounds of the general formula (IX)
HN ~ CF3
7 O ~ N ~ (IX)
R~ R10
in which ,
R7 has the abovementioned meaning,
Le A 28 306 - 17 -
2~9~6 23189-7323
and
R3 and Rl are different and represent hydrogen or
hydroxyl,
are first reacted with 1,1-thiocarbonyldiimidazole or
phenylthiocarbonyl chloride by the method described
under [B] to give the corresponding thiocarbonyl com-
pounds of the ~eneral formula (X)
HN ~ CF3
7 O ~ N
R ~ (X~
L
in which
R7 has the abovementioned meaning,
L represents the radical
Le A 28 306 - 18 -
2(3~9~6
23189-7323
--C-N~N --C-C6H5
S o~
and
then, as described under [L], the blocked hydroxyl group
(=OL) is eliminated and the primary hydroxyl function
is deblocked
or
in the case where Rl does not represent hydrogen or a
phosphoric acid derivative,
[D] ~ 2',3'-dideoxy-5-trifluoromethyluridine of the
formula (Ib)
o
H~ ~ CF3
O N (Ib)
~0~
HO ~
Le A 28 306 - 19 -
2~9~6 23189-7323
is reacted with compounds of the general formula (XI)
Rll-y (XI)
in which
Rll has the abovementioned meaning of Rl but does not
represent hydrogen or a phosphoric acid derivative
and
Y has the abovementioned meaning of T and is identical
to or different from this,
in inert ~olYents, if appropriate in the presence of a
base and/or of an auxiliary,
or in the case where Rl repreeents one of the above-
mentioned phosphoric acid radicals,
the compounds of the general formula (Ib) are fir~t
phosphorylated with phoephorus trichloride, trisimida-
zolylphoephine or phosphorue oxychloride and then if
appropriate with tributylammonlum diphoephate or with
compounds of the general formula (XII)
1~ ~I (XII)
R ~-P(Z)2
Le A 28 306 - 20 -
~649~6 23189-7323
in which
Rl2 represents a radical of the formulae
O O O ~ O
H0-P - H0 - P - -o-P-¦ H0-P -
oR2 ' ~ oR~4~ n Rs
in which
R2, R3, R4, R5 and n have the abovementioned meaning,
and
Z represents halogen, preferably chlorine,
in inert ~olvents, if appropriate in the presence of a
base and of an alkali metal halide, such as, for example,
sodium iodide, according to a cu~tomary method,
and in the case of the free hydroxymethyl function
(R1 ~ R), the respective protective group i8 eliminated
according to a customary method and/or a chromatographic
separation is optionally carried out.
Theproce3se~accordingtotheinvention can be illu3trated
by way of example by the following reaction scheme:
Le A 2B 306 - 21 -
,~ .
2~ 9~6
[A]
HNJ~CF, (H3C)35iNHSi(CH~)3/~ OSi(CH3)3
O~NH (NH,)2 SO~ (H,C)3SiOl~
(CH3)3sloso2cF3 / ~ CH,
CH~CN (CH3)~C-S!--O ~,~, OAc
0~ ~ _
HO ~ 2. chrom~L ~c$~-tlo~3 CH~ o N B
(CH~)~C-SI - O
Oq~N~
~C,
~ A 28 306 - 22 -
zie~9~6
[A] O
OSi(CH3)~ HNJ~CF3
1~ ' ~ Br CH2Ci2 O~ N
(CH~)35iO N -78'C / r.LC~HsCOO ~
~, Cl ml~tur~ p~r~tlon
CH,OH / I`IH,
0
HO~
Le ~ 28 306 - 23 -
.,
2~6~9~6
[A] O
J~, CF3
(CH3)C-Si--o HNJ~CF3 r.L CH3 o~N~
CH3 1~ O~NHJCH3CN/KOH/TDA-1(CH3)3C s! O~
. a- ml~tur-
~-pur~tlon
/F3COOH
O / o~
TDA~l: N(cH2cH2ocH2cH2ocHa)2 HNJ~CFa ~/ Cu~NF/THF/HOAe
2~(2~n~3~oxyt3~oxy)0~yl,~1n- 0 N
HO~
Le ~ 28 306 - 24 -
.
~. .
z~ 9~
[B] o
HN~CF,
CcHs COOOSi(CH3)3 ~J
1~0~0COCH3 N~ CF3 (CH3)3Sl0so2cF3 O~N
C~Hs COOOCO C6H~ (CH3)35iOlN~J CH3CN ~ C6Hs COO~
CsH5 COO OCO-C,Hs
CH30Na I
THF
N~ 3 ~CF3
C6H5~COOl O ¦ TCDI /CH3CN O~N
1.) i u3SnH / tolu~- ~ ,~ C~H~-COO ~
2.) TCDI/CH3CN ~ HO OH
3.) Su~SnH / ~olu~ S
Alr~'iN r
O N
C~H~COO~ TCDI:1,1 '-Th~ nYidi~zol~(N~N~;~=S
Le A 28 306 - 25 -
' . :, ' - , '
,
,
2~;gL91! 6
[B] o
1. DMTr.~CI, basu O~
O N 2. TCDI I CH3CN
HO ~ DMTrO
OH OH
1. 3u35n~olu~n~/AISN /
2. TCDI / CH3CN
~ r 3. 3u~SnHk~lu~ rA13N /
OCH3
[~ HN J~3, C F3
DMTr-CI C~H~ -C-CI OlN
DMTr -O~
OCH3
Le A 28 306 - 26 -
2C?~ 6
[B] O o
O ~ __ , 0
HO~ p TSOH HO~ > 120-C
HO OH
OCH3
o~ HN J~CF3
ACO ~ ~_ ACO ~
Le A 28 306 - 27 -
Z~?6-~9~6
[c]
o o
J~, CF3 ~ CF3
0~ N ~J 1. C~HsCOCI / pyrldl~-~ 0~ N
H0 ~0~ 2. TCDI / CH3CN C~HsCOO ~O~J
OH 0 ~ N ~
or Bu~Sn-H (Bu~Sn)2o /
tolu~no Dlo~ n~
AIBN / ~ AIBN
J~,, CF, o
O N ~ N11
C"HsCOO
Le A 28 306 - 28 -
2~ 9~6
[D]
~ocNH CO--O ~ NO2 DM F / r ~
J~ CF3COOH. r.L~L HN ~ 3
~oc NH Oo ~ CF3COOH x H2N OO
[D]
o o
HN ~ N ~ CF3
O~NJJ 1.POCI~/PO(OCH~ 1 O N
HO ~ 2. NSOH / pH 7,5 HO--P O
Le A 28 ~06 - 29 -
2~9~
[D]
o o
HN J~ J~ CF3
0~ N JJ 1. POCI3 / F~O(OCH3)3 1l O~ N
HO~ o I HO--F~--O-F~--O--P-Ol O ¦
y 2. ~Bu3NH)2 ~27H2 / DMF ONa lNa ONa ~7
\J 3. E~3NH~ HCOO
~. Nal / ~c~ton-
[D]
oSl~ I H~C-FOCI~/FO(OCII~ O~N~
HO ~ j 2. NaOH / pH 7,S NaO--P O
CH~
Le A 2 8 306 - 30
2C~9~6
[D]
o ~ C~ (CH~"-CO~CI /
p~rld~n-CH3'(CH2)12 COO ~
. [D~
HN ~ CF3 ~ CF,
HOl o ¦ ~. o N
~ æ~CH3)3CCO-O CH2 CI (CH3)3C CO-O~CH2~0 ~
The proces~e~ for the preparation of the compounds of the
general formula (I) according to the invention are
partially carried out in analogy to those method~ known
Le A?8 306 - 3I -
2~ 9~ 6
from the literature listed in the following [cf. M. Okabe
et al., J. Org. Chem. 53, 4780 (1980); V. Farina et al.,
THL 29, 1239, (1988); F. Seela et al., Heterocycles 29,
2193 (1989); R.R. Webb et al., Nucleosides Nucleotides 7,
147 (1988); EP 357,495; EP 199,451; EP 362,967; L. vrang
et al., Antiviral Res. 7, 139 (1987); EP 366,385;
EP 357,495; J.S. Driscoll, J. Med. Chem. 30, 862 (1987);
H. Shiragami, J. Org. Chem. 53, 5170 (1988)].
Suitable solvents for process variants [A] - lD] accord-
ing to the invention are inert or~anic solvents which do
not change under the reaction conditions. These prefer-
ably include ethers such as diethyl ether, dioxane,
tetrahydrofuran, glycol monomethyl ether or glycol
dimethyl ether, or halogenated hydrocarbon~ Cuch as
dichloromethane, 1,2-dichloroethane, trichloromethane or
tetrachloromethane, or amides such as dimethylformamide,
dimethylacetamide or hexamethylphosphoric triamide, or
hydrocarbons such as benzene, toluene or xylene, or
acetonitrile, nitromethane, sulpholane, dimethyl sul-
phoxide, ethyl acetate, or alcohols such as methanol,
ethanol, isopropanol, propanol or butanol, ethylene
glycol or pyridine. Mixtures of the solvents mentioned
can also be used. Methylene chloride and acetonitrile are
preferred for process variant [A], pyridine and dimethyl-
formamide for process variants [B] and [C] and dimethyl-
formamide and dimethyl phosphate for proceRs variant [D].
Suitable auxiliaries for the reaction with the compounds
of the general formula (IV) or (IVa) are, for example,
Le A 28 306 - 32 -
Z~9:~6
trimethylsilyl trifluoromethanesulphonate or trimethyl-
silyl trifluoroacetate or Lewis acids such as, for
example, tin(IV) chloride, titanium(IV) chloride, alumi-
nium(III) chloride, mercury(II) chloride or zinc(II)
chloride. Trimethyl~ilyl trifluoromethanesulphonate,
tin(IV) chlor~de, titanium(lV) chloride, aluminium(III)
chloride or mercury(II) chloride are preferred.
The auxiliaries are in general employed in an amount of
0.1 mol to 2.0 mol, preferably in molar amount~ relative
to 1 mol of the compounds of the general formulae (IV)
and (IVa).
Suitable bases are the cu~tomary inorganic or organic
base~ The~e preferably include alkali metal hydroxides
such as, for example, sodium hydroxide or potassium
hydroxide, or alkali metal carbonate~ such as ~odium
carbonate or pota~sium carbonate, or alkali metal alkox-
ides such as, for example, sodium methoxide or potassium
methoxide, or sodium ethoxide or potassium ethoxide, or
organic amines such as triethylamine, pyridine, picoline,
N-methylmorpholine, N-methylpiperidine, or tris-[2-(2-
methoxyethoxy)ethyl]amine~ or 1,8-diazabicyclot5.4.0~-
undec-7-ene (DBU) or 1,5-diazabicyclol4.3.0]non-5-ene
(D~N), or ammonium ~ulphate.
The base~ are in general employed in an amount from
1.0 mol to 3 mol, preferably from 1.0 mol to 1.2 mol, in
each ca~e relative to 1 mol of the compound~ of the
general formulae (IV), (IVa), (VI) or (IX).
Le A 28 306 - 33 -
.. ... ~- . .
.
The reaction temperatures can be varied within a broad
range with respect to the particular process step. In
general, the reaction is carried out in a range from
-40C to +170C, preferably from -40C to +150C.
All reactions in processes [A] to [D] can be carried out
at normal, elevated or at reduced pressure. The reactions
are preferably carried out at a pressure of 0.5 to 5 bar.
The elimination of the silylhydroxyl protective groups
(R6, if appropriate R7) in the compounds of the general
formulae (III), (Ia) and (VII) is carried out by custom-
ary methods, for example under the action of fluorine
salts such as, for example, tetrabutylammonium fluoride,
if appropriate in the presence of acetic acid and/or in
one of the abovementioned solvents, preferably in tetra-
hydrofuran, or in alcohols, preferably methanol, in thepresence of p-toluenesulphonic acid.
The fluorine ~alts are employed in an amount from 1 to
3 mol and the acetic acid in an amount from 1 to 5 mol,
in each case relative to 1 mol of the compound~ of the
general formulae (III) and (Ia).
In the case where R7 together with the oxygen atom forms
an ester radical, the elimination is in general carried
out in one of the abovementioned alcohols, such as
methanol or ethanol, preferably in methanol in the
presence of ammonia.
Le A 28 306 - 34 -
2~ 9~6
Th el$minations are preferably carried out in a tempera-
ture range from -10C to +30C and under normal pre~sure.
Tin hydrides, such as, for example, tributyltin hydride,
triphenyltin hydride or tin oxides such as, for example,
tetrabutyltin oxide are suitable for reducing the com-
pounds of the general formulae (VIII) and (X). Tributyl-
tin hydride and tetrabutyltin oxide are preferred.
The reduction is carried out in one of the abovementioned
solvents, preferably in dioxane or toluene.
Suitable cataly~ts for the reduction are, for example,
azobisisobutyronitrile (AIBN) and dibenzoyl peroxide.
Azobiqisobutyronitrile (AIBN) is preferred.
The catalyst is in general employed in an amount from
0.005 mol to 0.5 mol, preferably from 0.01 mol to
0.05 mol, in each case relat$ve to 1 mol of the compounds
of the general formulae (VIII) and (X).
The hydrogenation is carried out in one of the abovemen-
tioned alcohols, for example methanol, ethanol or pro-
panol in the pre~ence of a noble metal cataly~t ~uch as
platinum, palladium, palladium on animal charcoal or
Raney nickel, in a temperature range from 0C to +50C,
preferably from room temperature to +40-C at normal or
elevated pre~ure.
Le A 28 306 - 35 -
.
2[?Ei~9~
Besides the abovementioned solvents, suitable solventsfor the preparation of the corresponding mono-, di- or
triphosphates and alkyl phosphonates [D] of the compounds
of the general formula (I) according to the invention are
also phosphoric acid esters such as, for example, tri-
methyl phosphate or triethyl phosphate.
Suitable bases for establishing a pH of 7.5 are prefer-
ably alkali metal hydroxides such as sodium hydroxide or
potassium hydroxide.
For the preparation of the phosphates, triethylammonium
hydrogen carbonate i~ preferably employed as a buffer.
In the case of the preparation of the triphosphates of
the general formula (I), the dichlorophosphate inter-
mediate formed in the reaction with phosphorus oxy-
chloride i8 not hydrolysed to the monophosphate, butreacted directly with bis(tributylammonium) pyrophosphate
to give the corresponding triphosphate.
~he reactions of the compounds of the general
formula (VIII) (X = -S) with trialkyl phosphite~ is
carried out in analogy to methods known from the litera-
ture (cf. J. Org. Chem. 1989, 54, 4780).
~he elim~nation or the replacement of hydroxyl protective
groups and amino protective groups i8 in general carried
out by customary methods, ~uch as are described, for
example, in Greene, Protective Groups in Organic
Le A 28 306 - 36 -
- 2~9~6
Synthesis, John Wiley & Sons, 1981, 10 ff and 218 ff.
The preparation of the compounds of the general
formula (I) according to the invention, in which R1
represents an amino acid radical ~D], is carried out by
elimination of the respective protective group, if
appropriate with activation of the corresponding acid and
esterification with the free hydro~ymethyl function by
the methods customary in peptide chemistry [cf. Houben-
Weyl, Eugen Muller, ~Methoden der organischen Chemie
(Methods of Organic Chemistry)", Volume XV/l and XV/2,
Georg Thieme Verlag, Stuttgart, 1974].
1,8-DiazabicycloE5.4.0]undec-7-ene (DBU) is preferably
employed as the base in thi~ ca~e.
5-Trifluoromethyluracil of the formula (II) i~ known.
The compounds of the general formula (III) are known per
se or can be prepared by a method known from the litera-
ture (cf., for example, Khim Geterotsikl. Soedin, (8),
1128-31, (1), 101-10 and THL, 22 (11), 1029-32].
The compound~ of the general formulae (IV) and (IVa) are
known per se or can be prepared by processes known from
the literature [cf., for example, J. Org. Chem. 53, 4780
(1988); THL ~2~ 1239 (1988) and Heterocycles 29, 2193
(1989); Khlm. Geterotsikl. Soedin (1), 101-10 and (8),
1128-31].
The compounds of the general formulae (Ia) and (Ib) are
Le A 28 306 - 37 -
2 ~ ~ 9~ 6
new and can be prepared by the processes mentioned above.
The compounds of the general formulae (v)~ (VII ) and (IX)
are known per se or can be prepared by a customary method
[cf. J. Med. Chem. 30 (2), 440-4; JY 63,188,696].
Some of the compounds of the general formula (X) have
been previously described in the case where L represents
the radical -(C=S~-C~H5 (cf. JP 028,408) or are new and can
then be prepared by the abovementioned process.
The compounds of the general formula (VI) are known [cf.
Anal. Biochem. 60, 608 (1974); MSD Book 2, 371 A].
The compounds of the general formulae (XI) and (XII)
are known [cf. Houben-Weyl, Eugen-Muller, Methoden der
organischen Chemie (Methods of Organic Chemistry),
Volume XV/l and XV/2, Georg Thieme Verlag, Stuttgart 1974
and Amino Acid~, G.C. Barrett, London, New York, Chapman
and Hall 1985].
It ha~ 6urpri6ingly been found that the compounds of the
general formula (I) according to the invention have an
extremely strong specific action against the hepatitis B
Le A 28 306 - 38 -
2~ 6
virus (HBV). Detection was carried out in hepatoma cells
(HEP G2.2.15) transfected with hepatitis B virus DNA.
The results ~f the examples listed ~elow were determined
for the HBV test system described in the following
literature reference [Sells, M.A.; Chen, M.L., Acs, G.,
Proc. Natl. Acad. Sci. USA pp. 1005 - 1009, Vol. 84
(1987)]:
Transfected hepatoma cells (HEP G2.2.15) were incubated
with various concentrations of the respective compound.
By treatment of the tran~fected hepatoma cell line
HEP G2.2.15 with the compounds according to the inven-
tion, it was possible to show the occurrence of virus-
specific HBV DNA in the aupernatant as well as a reduc-
tion in the HB~Ag level. It wa~ further found that the
compounds according to the invention lead to a reduction
of the replicative intermediates of the hepatitis
viruses. The content of HBV DNA was determined in the
supernatant of the cell cultures after PEG precipitation.
Thi3 wao carried out using a non-radioactively labelled
HBV genomic DNA sample [Pauly, P., 1982, P.H.D. Thesi~,
Unlver~ity of Gottingen, F.R.G.; Rochel et al., 1990,
EMBL, Acce~ion No. X 51790]. Determina~ion of the
influencing of HB,Ag formation was simultaneou~ly carried
out by mean~ of a commercially available Elisa test. The
IC~o values given relate to the substrate concentrations
which, under the abovementioned te~t conditions, cause a
50 ~ inhibition of the HBV DNA concentration in the
supernatant.
Le A 28 306 - 39 -
Z~
Ex. No. ICso(nM)
2 0.01
> 0.25
The pos~ibly present cytotoxic influence of the compounds
according to the invention took place simultaneously by
means of crystal violet colouration or via the incor-
poration of radioactively labelled thymidine into the
cellular DNA.
In comparison thereto, the substances DDA and DDC known
from the literature (cf. Ueda et al., Virology 169:
213-216 (1989) show the followinq IC50 values in the
abovementioned test system: DDA > 100 ~m and DDC = 5 ~m.
The action of Example 2 on other cells was tested by
incubation of HEL and MEF cells. No affect on the viabil-
ity of these cells was shown up to a concentration of250 ~M.
The compounds according to the invention are useful
active substances in human medicine for the treatment of
virus-induced hepatitis, caused by Hepdna viruses, such
as hepatitis B viruses, hepatitis C viruses or hepatitis
delta viruses, in particular hepatitis 8 viruses.
Examples of indication area~ which can be mentioned in
human medicine are:
Le A 28 306 - 40 -
2~ 9~ ~;
The treatment of chronic hepatitis B, C and delta virus
infections and the treatment of acute hepatitis B, C and
delta virus infections, in particular of chronic and
acute hepatitis B virus infections.
The present invention includes pharmaceutical prepara-
tions which, in addition to non-toxic, inert pharmaceut-
ically suitable excipients, contain one or more compounds
of the formula (I) or which consist of one or more active
substances of the formula (I), and processes for the
production of these preparations.
The active substances of the formula (I) should be
present in the abovementioned pharmaceutical prepara-
tions, preferably in a concentration of about 0.1 to
99.5 % by weight, preferably of about 0.5 to 95 % by
weight of the total mixture.
Apart from the compounds of the formula (I), the above-
mentioned pharmaceutical preparation~ can also contain
further pharmaceutical active sub~tances.
The abovementioned pharmaceutical preparations are
prepared in a customary manner by known methods, for
example by mixing the active substance or sub~tance~ with
the excipient or excipients.
In general, it has proved advantageous both in human and
in veterinary medicine to administer the active substance
or sub~tances according to the invention in total amount~
Le A 28 306 - 41 -
2~ 9~6
of about O.S to about S00, preferably 1 to 100, mg/kg of
body weight per 24 hours, if appropriate in the form of
several individual doses, to achieve the desired results.
An individual dose contains the active substance or
substances preferably in amounts from about 1 to
about 80, in particular 1 to 30, mg/kg of body weight.
~owever, it may be necessary to depart from the dosages
mentioned, in particular depending on the nature and the
body weight of the 4ub~ect to be treated, the nature and
the severity of the disease, the type of preparation and
of administration of the medicament and the time or
interval within which administration takes place.
Startina com~ounds
Exam~le I
1-(2,3,5-Tri-O-benzoyl-~-D-ribofuranosyl)-5~trifluoro-
methy~-uracil
~ CF3
O~N
C6H5-COO'\~O ~J
~ .
C6Hs-COO OCOC6H5
~e A 28 306 - 42 -
2~l9~6
A stirred suspension of S.0 g (27.8 mmol) of S-(tri-
fluoromethyl)uracil in 139 ml (0.66 mol) of hexamethyl-
disilazane was treated with 211 mg (1.39 mmol) of an-
hydrous ammonium sulphate and heated to reflux for S h
S under an atmosphere of nitrogen. The hexamethyldisilazane
was then distilled off in a slight vacuum and the residue
was dissolved in 370 ml of anhydrous acetonitrile.
13.31 g (26.40 mmol) of 1-O-acetyl-2,3,5-tri-O-benzoyl-
~-D-ribofuranose were added, the mixture was cooled to
0C and 7.0 ml (36.14 mmol) of trimethylsilyl trifluoro-
methanesulphonate were added dropwise in the course of
30 min. The cooling bath was removed, and the reaction
solution was subsequently stirred at room temperature for
a further 1 h. It was then stirred into a cold mixture of
170 ml of saturated NaHCO3 solution and 200 ml of ethyl
acetate. The phases were ~eparated and the water phase
was extracted with 2 x 200 ml of ethyl acetate. The
combined extracts were dried over MgSO4, the solvent was
evaporated in vacuo and the residue was chromatographed
on 209 g of silica gel (toluene : ethyl acetate 4:1).
15.3 g (88 %) of the title compound were obtained as a
colourless foam.
Rr = 0-35 (toluene : ethyl acetate 4:1)
MS (FAB) m/z - 625 (M+H)+
Le A 28 306 - 43 -
2~6-~9~7 ~
Example I I
1-(5-O-Benzoyl-~-D-ribofuranoyl)-5~rifluoromethyl~uracil
HN ~ CF3
O ~ N
C6H5-COO~
OH OH
In analogy to S.N. Shino et al., Tetrahedron 41, 5503
(1985), 10.90 g (17.50 mmol) of the dried compound from
~xample I were added in portions to a stirred suspension
of 2.36 g (43.6 mmol) of sodium methoxide in 200 ml of
anhydrous THF at 0C. The cooling bath was removed, and
the reaction mixture was subsequently stirred at 0C for
1 h and neutralised (pH 6.5) by addition of
Dowex 50 W-X 4 Lon exchanger (H~ form). The ion exchanger
was removed by filtration and washed with 3 x 20 ml of
ethanol. The filtrate was concentrated to dryness in
vacuo and chromatographed on 285 g of ~ilica gel (di-
chloromethane : methanol 95:5). 4.48 g (62 %) of the
title compound were obtained as colourles~ c.rystal~.
m.p.s 186C
R~ = 0.40 (dichloromethane : methanol 9:1)
MS (FAB) m/z = 417 (M+H)
Le A 28 306 - 44 -
2 ~ ~ 9~ 6
Example III
1-(5'-0-Benzoyl-~-D-ribofuranosyl)-5-trifluormethyl-uracil-
2',3'-thionocarbonate
~ CF3
O ~ N
C6Hs-COO ~
0~0
S
A solution of 3.33 g (8.0 mmol) of the compound from
Example II in 150 ml of anhydrous acetonitrile was
treated in portions with 3.60 g (18.16 mmol) of 1,1~-
thiocarbonyldiimidazole and stirred at room temperature
for 2 h. The ~olvent was then evaporated in vacuo and the
residue was purified by filtration on 100 g of silica gel
(toluene s ethyl acetate 3s2). 3.26 g (89 ~ of theory) of
the title compound were obtained as a colourless powder.
m.p.~ 133C (dec.)
F~ ~ O.71 (ethyl acetate)
IR (KBr):y = 3188, 3073, 1697, 1469, 1379, 1326,
1270, 1144, 1097, 1012, 720 cm~1.
MS (FAB) m/z = 459 (M+H)+, 475 (M+Na)+
Le A 28 306 . - 45 -
2~
Example IV
5~-O-Benzoyl-2r,3'-didehydro-2',3'-dideoxy-5-(trifluoro-
methyl)-uridine
HN ~ CF3
O ~ N
C6H5-COO~
3.00 g (6.55 mmol) of 1-(5'-O-benzoyl-~-D-ribofuranosyl)-
5-trifluoromethyl-uracil-2',3'-thionocarbonate
(Example III) were added in one portion to 75 ml
(66 equiv.) of freRhly distilled triethyl phoRphite
preheated to 130C under a nitrogen atmosphere and the
mixture was heated at 130C (exactlyl) for l.S h. The
reaction mlxture was then cooled, 10 ml of toluene were
added and it was concentrated to dryness on a rotary
evaporator. This process was repeated twice more in order
to remove the la~t residues of triethyl phosphite. 20 ml
of ether were added to the still toluene moist residual
crystal magma, and it was well ~tirred, filtered off with
suction, washed with a little ether and dried over
Sicapent in a high vacuum. A further quantity of the
title compound was obtained by concentration o~ the
Le A 28 306 - 46 -
Z ~ ~ ~ 9 ~6
filtrate. Total yield 1.59 g (63 ~) of colourless crys-
tals. A further 230 mg (9 %) of the title compound were
obtained by chromatography of the mother liquor on 40 g
of silica gel (toluene : ethyl acetate 7:3~.
m.p.: 157C
Rf = 0.24 (toluene : ethyl acetate 7:3)
MS (FAB-): m/e = 381 (M-H) .
IR ~RBr): v = 3434, 3181, 3065, 1703, 1462, 1327, 1280,
1147, 1120, 1098, 1043, 708 cm~
Example V
2'-Deoxy-5'-0-(4-methylbenzoyl)-5-(trifluoromethyl)-
uridine
H3C ~ OO N
HO
A eolution of 290 ~1 (2.20 mmol) of p-toluoyl chloride in
12 ml of pyridine was added dropwi~e in the cour~e of 2 h
to a solution, cooled to 0C, of 593 mg (2.00 mmol) of
2'-deoxy-5-(trifluoromethyl)-uridine (Trifluridin ) in
Le A 28 306 - 47 -
2~ 9~
12 ml of anhydrous pyridine under a nitrogen atmosphere.
The mixture was then stirred at 0C for lS min and then
10 ml of anhydrous methanol were added dropwise to
destroy excess p-toluoyl chloride. The cooling bath was
removed and the reaction mixture was concentrated in
vacuo and the residue was chromatographed on 85 g of
silica gel (dichloromethane : methanol 9:1). 71 % of the
title compound were obtained as colourless crystals.
m.p.: 214C
R~ = 0.31 (dichloromethane : methanol 9:1)
MS (FAB): m/e = 415 (M+H)+
Example VI
2'-Deoxy-3'-0-(imidazolyl-thiocarbonyl)-5'-0-(4-methyl-
benzoyl)-5-(trifluoromethyl)-uridine
o
HN ~ CF3
H3C ~ 00 ~ N ~
O ~q
S ~ N
Le A 28 ~ - 48 -
2~
A suspension of 410 mg (0.99 mmol) of the compound from
Example V in 15 ml of anhydrous acetonitrile was treated
with 353 mg tl.98 mmol) of 1,1'-thionylcarbonyldiimid-
azole and stirred at room temperature for 25 h. The
solvent was evaporated in vacuo without heating and the
residue was stirred into a mixture of 10 ml of ethyl
acetate, 10 ml of saturated NaCl solution, 5 ml of
saturated NaHCO3 solution and 5 g of ice. The organic
phase was separated off and the aqueous phase was ex-
tracted with 10 ml of ethyl acetate. The combined ex-
tracts were dried over MgSO4, the ~olvent was evaporated
in vacuo and the residue was triturated with a little
ether. 474 mg (91 %) of thiocarbonylimidazolide were
obtained as a colourless powder.
m.p.: 87C
R2 = 0-30 (dichloromethane : THF 4:1)
MS (FAB) m/e = 525 (M+H)+
IR (KBr): v = 3424, 1700, 1128 cm-l
Le A 28 306 - 49 -
2~6~9~L6
Preparation Examples
Example I
5'-(tert-Butyldimethyl~ilyl)-2',3'-dideoxy-5~tri-
fluoromethyl)-uridine
(Anomer mixture)
CH3 HN ~ CF3
(CH3)3C-Si- O N
CH3 ~
A ~tirred mixture of 0.54 q (3.0 mmol) of 5-(trifluoro-
methyl)-uracil (dried at 80C ior 24 h) and 21.1 ml
(100 mmol) of hexamethyldisilazane was heated at 140C
for 1 h under an atmosphere of nitrogen in the pre~ence
of 20 mg (0.15 mmol) of ammonium ~ulphate. The clear
solution wa~ allowed to cool and the volatile con~titu-
ent~ were di~tilled off in vacuo. trhe re~idual oil was
treated with 5 ml of anhydrou~ toluene and the volstile
con~tituents were again distilled off in vacuo. The
residual oil was dl~olved in 40 ml of anhydrou~ aceto-
nitrile, 0.82 g (3.0 mmol) of 1-O-acetyl-5-(tert-butyl-
dimethyl~ilyl)-2',3'-dideoxyribose ~M. Okabe et al.,
J. Org. Chem. 53, 4780 (1988)] wa~ added and the mixture
Le A 28 306 - 50 -
2Q6~9~
was cooled to -10C. 0.64 ml (3.3 mmol) of freshly
distilled trimethylsilyl trifluoromethanesulphonate was
added dropwise to this mixture and it was subsequently
stirred at -10C for 30 min. The reaction solution was
then stirred into a mixture of 50 ml of saturated NaHCO3
solution and 50 ml of ethyl acetate. The organic phase
was separated off and the aqueous phase was extracted
with 25 ml of ethyl acetate (twice). The combined organic
phases were dried over MgSO4. Evaporation of the solvent
in vacuo gave 1.15 g (97 ~) of the title compound as an
oil (mixture of anomers) which was further reacted without
further purification.
Rs = 0.83, 0.76 (ethyl acetate)
MS (FAB) m/e = 395 (N+H)+.
Examvle 2 and Example 3
~-2',3'-Dideoxy-5-~rifluoromethyl)-uridi ne ( Example 2)
H~ ~ CF3
o N and
"~
Le A 28 306 - 51 -
2C~6~L9~6
~-2',3'-dideoxy-5~trifluoromethyl)-uridine (Example 3)
N
o~ 11
HN ~
CF3
o
A solution of 1.15 g (3.0 mmol) of the anomer mixture
obtained in Example 1 and 628 mg (3.3 mmol) of p-toluene-
sulphonic acid monohydrate in 8 ml of methanol and 1.2 ml
of water was stirred at room temperature for 30 min.
0.84 ml (6.0 mmol) of triethylamine was then added. After
evaporation of the solvent in vacuo and chromatography of
the residue on 130 q of silica gel (toluene : ethyl
acetate l:1), 303 mg t36 %) of the non-polar ~-isomer
(Example 2) were obtained as colourless crystals.
m.p.: 165C
Rr = 0.46 (ethyl acetate); 0.27 (dichloromethane
methanol 9:1)
HPLC purity ~ 99.5 ~
MS (DCI, NH3) m/e = 281 (N+H)t, 298 (M+NH4)t
IR (XBr): 3466, 3192, 3074, 1706, 1461, 1410, 1334, 12B6,
1141, 1092, 1066, 1040, 614 cm~1.
lH-NMR (250 NHz, CD30D): 6 = 1.90 - 2.50 (m, 4H, H-2~,
H-3'); 3.70, 3.98 (AB, 2H, J = 12.5 Hz, 2.5 Hz, H-5');
4.20 (m, lH, H-4'); 6.01 (dd, lH, J = 7.0 Hz, 1.5 Hz,
Le A 28 306 - 52 -
2~6~9~
H-l~); 8.98 (8l lH, H-6).
CloHllF3N204 (280.21)
Calc.: C 42.87 H 3.96 N 10.00
Found: C 42.7 H 4.0 N 9.9
270 mg (32 %) of the polar ~-isomer (Example 3) were
additionally obtained as a colourless foam.
R~ = 0.36 (ethyl acetate)
HPLC purity = 99 %
MS (DCI, NH3) m/e = 281 (M+H)t, 298 (M+NH4)+
IR ~RBr): 3448, 1702, 1473, 1412, 1334, 1276, 1129,
612 cm~l
lH-NMR (250 MHz, CD30D): ~ = 1.85 - 2.00 (m, 3H, H-2~,
H-3'); 2.51(m, lH, H-2'); 3.54 (dd, lH, J = 12.5 Hz,
6 Hz, H-5'); 3.66 (dd, lH, J = 12.5 Hz, 3.5 Hz, H-5');
4.50 (m, lH, H-4'); 6.00 (dd, lH, J = 6.5 Hz, 5.5 Hz,
H-l~); 8.00 (8~ lH, H-6).
The compound from Example 2 can additionally be prepared
as follows:
150 mg (0.4 mmol) of 5~-0-benzoyl-2~,3'-dideoxy-5-tri-
fluoromethyluridine were added to a solution of 25 mg
(0.45 mmol) of sodium methoxide in 11 ml of anhydrous
methanol and the mixture wa~ stirred at room temperature
for 1.6 h. The reaction mixture wa~ then neutralised by
addition of Dowex 50 X 4 ion exchanger (H~ form), the ion
exchanger wa~ removed by filtration and the filtrate was
evaporated to dryness in vacuo. By trituration with
ether~pentane, 104 mg (93 %) of the title compound were
obtained as colourless cry~tal~.
Le A 28 306 - 53 -
2 ~ ~ ~9 ~ S
m.p.: 165C
Example 4
~-5'-(2,2-Dimethylpropanoyloxymethyl)-2',3'-dideoxy-5-
~rifluoromethyl)-uridine
HN ~ CF3
(H3C)3C 0
~,o~J
A solution of 150 mg (0.54 mmol) of ~-2~,3~-dideoxy-5-
trifluoromethyluridine in 10 ml of anhydrous DMF was
slowly added dropwise to a stirred su6pension, cooled to
0C, of 18 mg (0.59 mmol) of sodium hydride (80 %
etrength in oil) in 1 ml of anhydrous DMF. After evolu-
tion of hydrogen had ended (about 2 h), a ~olution of
89 mg (0.59 mmol) of pivaloyloxymethyl chloride in 1 ml
of anhydrous DMF was added, the cooling bath was removed
and the mixture was subsequently stirred at room tempera-
ture for 70 h. The largest part of the solvent was
evaporated in vacuo, care being taken that the tempera-
ture did not exceed 35C. The residue was taken up in a
mixture of 10 ml of water and 10 ml of ethyl acetate. The
organic phase was separated off and the water phase was
Le A 28 306 - 54 -
Z~ 9~ 6
extracted with 10 ml of ethyl acetate (twice) and the
combined organic extracts were dried over MgS04. After
evaporation of the solvent in vacuo and chromatography of
the residue on 24 g of ~ilica gel (toluene : ethyl
aceta~e 7:3), 134 mg (66 %) of the title compound were
obtained as a colourle~s foam.
R~ = 0.58 (ethyl acetate)
MS (DCI, NH3) m/z = 395 (M+H)+, 412 (M+NH4)'
IR (KBr): ~ = 3530, 2983, 1737, 1685, 1473, 1288,
1133, 785 cm~1.
Example 5
~-5~ Ethoxycarbonyl~oxy-eth-l-yl)-2',3'-dideoxy-5-
(trifluoromethyl)-uridi ne
~ CF3
A~ de~cribed for Example 4, 62 mg (47 ~) of the title
compound were obtained from 100 mg (0.36 mmol) of ~-
2~,3'-dideoxy-5-~rifluoromethyl)-uridine and 62 mg
(O.40 mmol) of l-chloro-l-ethoxycarbonyloxyethane after
chromatography of the crude product on 8 g of ~ilica gel
(toluene : ethyl acetate lsl) as colourless crystal~.
m.p.: 114-C
Rf = 0. 33 ( tol uene: ethyl acetate 1:1)
MS (DCI, NH3) m/z = 353 (C13H15F3N206+H) , 370 (M+NH4)
IR (KBr):~ 3019, 1704, 1277, 1220, 1212 cm 1
Le A 28 30 ~ 55 ~
2~;9L9 6
Exam~le 6
~-5-Hemisuccinyl-2',3'-dideoxy-5~rifluoromethyl~-uridine
0 HN
HO~o 0 ~ N
O ~ ..
A solution of 100 mg (0.36 mmol) of ~-2~,3'-dideoxy-S-
trifluoromethyluridine in 4 ml of anhydrous pyridine was
treated with 54 mg (0.54 mmol) of succinic anhydride and
the mixture was stirred at room temperature for 65 h.
After evaporation of the solvent in vacuo and chromato-
graphy of the crude product on 30 g of ~ilica gel (di-
chloromethane : methanol 9:1), 96 mg t70 %) of the title
compound were obtained as a pale solid.
R~ 8 0 ~ 1 9 ( dichloromethane : methanol)
MS (FAB) m/z = 381 (M~H)+.
Le A 28 306 - 56 -
2~9~6
Example 7
5~-O-[(tert-~utoxycarbonyl)-L-leucyl)]-2~,3'-dideoxy-5-
(trifluoromethyl)~uridine
~ ,
H3C
CH3
A stirred solution of 150 mg (0.54 mmol) of ~-2~,3'-
dideoxy-5-trifluoromethyluridine and 634 mg (1.08 mmol)
of ~tert-butoxycarbonyl)-L-leucine-4-nitrophenyl ester
[Houben-Weyl 15/2 p. 33] in 3 ml of anhydrous DMF was
treated with 162 ~l (1.08 mmol) of DBV and stirred at
room temperature for 48 h. The solvent was then largely
evaporated in vacuo and the residue was taken up in 40 ml
of ethyl acetate. The organic phase was washed wlth 20 ml
each of 10 % strength Na2CO3 solution, water and saturated
NaCl solution and dried over MgSO4. After evaporation of
the solvent in vacuo and chromatography of the residue on
40 q of silica gel (toluene s ethyl acetate 1:1), 195 mg
t73 %) of the title compound were obtained as a colour-
less foam.
Rf = 0.69 (ethyl acetate)
MS ( FAB ) m/z = 494 ( M+H ) +
IR (KBr): ~ = 2965, 1703, 1470, 1369, 1275, 1162,
1091, 1036 cm~1.
Le A 28 306 - 57 -
R~ = 0.69 (ethyl acetate)
Example 8
5'-0-(L-Leucyl)-2',3'-dideoxy-5~trifluoromethyl)-uridine
hydrochloride
HCIxH
CH3
A stirred suspen~ion, cooled to +5C, of 99 mg (0.2 mmol)
of the compound from Example 7 in 1 ml of anhydrous
dioxane was ~lowly treated with 1 ml of a 4 N solution of
gaseous hydrogen chloride in anhydrous dioxane and
~tirred at +5C for 30 min and at room temperature for
4 h. 5 ml of toluene were then added and the mixture was
concentrated in vacuo. This process was repeated, then
the residue wa~ triturated with 5 ml of etherr filtered
off with ~uction and dried over KOH in a high vacuum.
76 mg (96 %) of the title compound were obtained a~ a
colourless powdex.
R~ = 0.44 (acetonitrile : water 9:1)
MS (FAB) m/z = 394 (M+H)+
IR (KBr): y = 3433, 2965, 1701, 1472, 1413, 1276,
1132, 1090, 1038, 616 cm~l.
,~e A 28 306 - 58 -
Z~ 9~ ~
Example 9
2',3'-Dideoxy-5-~rifluoromethyl)-uridine-5'-mono-phosphate,
sodium salt
HN ~ CF3
O O ~ N
HO-P O ~ i
ONa ~
A ~uspension, cooled to -10C, of 100 mg (0.36 mmol) of
~-2',3'-dideoxy-5-~rifluoromethyl)-uridine (Example 2) in
1 ml of trimethyl phosphate was treated with 67 ~1
(0.71 mmol - 2 equiv.) of phosphorus oxychloride and -
stirred at 0C for 24 h. It wa~ then poured into 10 ml of
ice-water and a pH of 7.5 was established using 2 N NaOH.
The aqueous solution was freed of organic material by
extraction with dichloromethane and ether, concentrated
in vacuo to a volume of about 1 ml and chromatographed on
40 ml of Diaion HP-20 (water). The product-containing
fractions were collected, freeze-dried, taken up in 1 ml
of water and chromatographed on a Lobar ready-to-use
column ~ize B (310-25) Lichroprep., RP-8 (40-63 ~m) with
water. The product-containing fractions were collected
and freeze-dried. 129 mg (93 ~) of the title compound
Le A 28 306 - 59 -
2~ 9~6
were obtained as a colourle~s lyophilisate.
R = 0.33 (acetonitrile : water 8:2)
IR (KBr): ~ = 3430, 1702, 1066, 860, 545 cm~l.
Exampl e 10
2r,3'-Dideoxy-5~trifluoromethyl~uridine-5'-triphosphate,
trisodium salt
~ CF3
O O O O N
HO -P-O- P O-P O ~
ONa ONa ONa ~
A ~olution, cooled to 0C, of 150 mg (0.54 mmol) of
2',3'-dideoxy-5-~rifluoromethyl~uridine (Example l) in
1 ml of trimethyl pho~phate was treated with 0.11 ml
(1.2 mmol) of pho~phorus oxychloride and stirred at 0C
or 18 h. 0.57 ml (2.40 mmol) of tributylamine and 6.7 ml
(2.70 mmol) of a 0.4 M solution of bis-(tributylam-
monium)pyrophosphate ~D.E. Hoard et al., J. Am. Chem.
Soc., 87, 1785 (1965)] were then added dropwiqe at 0C in
DMF. After 25 min at 0C, the reaction was discontinued
by addition of 9 ml of 1 M aqueous tributylammonium
hydrogen carbonate (TEAB) buffer and a pH of 7.4 wa~
establi~hed. The water phase was extracted with S x 50 ml
of dichloromethane and then the mixture was ad~usted to
Le A 28 306 - 60 -
~ 9~ 6
pH 1.5 by addition of 4 ml of Dowex 50 W-X 4 (H~ form).
The ion exchanger was removed by filtration and the clear
filtrate solution was chromatographed on 40 ml of
Sephadex A 25 (Pharmacia), which was equilibrated with
0.1 M TEAB. The column was eluted with an increasing
gradient (0.1 M per 20 ml of eluate) of TE~B buffer of
0.1 M to 0.5 N. The product-containing fractions were
concentrated to dryness on a rotary evaporator, treated
with a little methanol and again concentrated to dryness.
This process was repeated a further 5 times, then a
solution of the crude product in 3 ml of methanol was
treated with 3 ml (3 mmol) of a 1 M solution of sodium
iodide in acetone, as a result of which the triphosphate
precipitated a~ the sodium salt. The precipitate obtained
was washed a further 3 times with 5 ml of acetone
(centrifuge) and then dried over P40lo (phosphorus
pentoxide) in a high vacuum. 169 mg (54 % of theory) of
the title compound were obtained as a colourle~s solid.
R = 0.18 (acetonitrile : water 4:1)
IR (KBr): y = 3433, 1706, 1478, 1277, 1103, 997,
896, 769 cm~ 1.
Le A 28 306 - 61 -
2~ 9~ 6
Example 11
2',3'-Dideoxy-S-~rifluoromethyl)-uridine!-5'-methyl-
phosphonate
~ CF
O O N
NaO-p o ~ O
CH3 ~
A Rolution, cooled to 0C, of 100 mg (0.36 mmol) of
2',3'-dideoxy-5-trifluoromethyluridine ~Example 1) in
1 ml of trimethyl phosphate was treated with 71 mg
(0.54 mmol) o methanephosphonyl dichloride and allowed
to stand at -22C for 28 h. The reaction mixture was then
treated with 8 ml of anhydrous dichloromethane, added to
25 ml of cold water and ad~usted to a pH of 8.0 by
addition of 1 N NaOH solution. The water phase was
extracted several times with dichloromethane and then
freeze-dried. After chromatography of the crude product
on Diaion HP 20 (water) and freeze-drying of the product-
containing fractions, 63 mg (48 %) of the title compoundwere obtained as a colourle~s lyophilisate.
Rt - 0.32 (acetonitrlle : water 4sl)
IR (KBr):y = 3448, 1629, 1467, 1201, 1029, 949, 808 cm 1
MS (SIMS) m/z = 369 (M+Na)+.
~e A 28 306 - 62 -
2~6~9~6
Exam~le 12
~-2',3'-Dideoxy-5-~rifluoromethyl~uridine sodium salt
Na N J~ CF3
0 ~ N
H0 ~
A solution of ~-2',3~-dideoxy-5-trifluoromethyl-uridine
in 10 mlof THFwas added dropwi3e to a stirred su pension,
cooled to 0C, of 105 mg (3.50 mmol) of sodium hydride
(80 ~ in oil) in 5 ml of anhydrous THF. The cooling bath
was removed and the mixture was stirred until evolu~ion
of gaq was complete (about 10 min.). The solvent was then
evaporated in vacuo and the re~idue was dis~olved in
20 ml of di3tilled water. The water phase was extracted
with 10 ml of ethyl acetate (3 times), freed of solvent
residuee in vacuo, filtered through a Millipore membrane
filter (0.22 ~) and freeze-dried.
971 mg (90 %) of the title compound were obtained as a
colourle~s, hlghly water-soluble lyophilisate.
Rr = 0.46 (ethyl acetate)
HPLC puritys ~ 99 %
Le A 28 306 - 63 -
Z~ 9~ 6
Exam~le 13
S'-O-Benzoyl-2',3'-dideoxy-5~trifluoromethy~-uridine
~ CF3
O ~ N
C6H5-COO'\~
Other preparation possibilities:
Method A:
410 mg (1.07 mmol) of the compound from Example IV were
added in one portion to a suspension of 120 mg of pre-
hydrogenated palladium on carbon (10 %) in 40 ml of THF
(p.a.) and the mixture was hydrogenated for 1 h at 20C
and 1 atm of hydrogen (if required, a further 60 mg of
the catalyst are added and the mixture i8 hydrogenated
for a further 1 h at room temperature). After conclusion
of the reaction (TLC), the catalyst was removed by
filtration on about 10 g of kieselguhr washed with THF,
the filtrate was concentrated in vacuo and the re idue
wa~ chromatographed on 25 g of silica gel (toluene :
ethyl acetate 3:2). 304 mg (74 %) of the title compound
were obtained as a colourless foam which cry~tallised
Le A 28 306 - 64 -
2C~ 9~ ~
slowly from ether/pentane.
m.p.: 93C
Rf = O . 35 (toulene : ethyl acetate 3:2);
Rf = O . 56 (ethyl acetate)
MS (DCI, NH3): m/e = 385 (M+H)+, 402 (M+NH4)+
IR (Rsr): ~ = 3222, 3084, 1722, 1466, 1412, 1278, 1124,
1084, 1037, 713 cm~
Method B:
A suspension of 0.92 g (2.00 mmol)of the compound from example III
in 50 ml of anhydrous toluene was treated with 44 mg
(0.27 mmol) of ~ azoisobutyronitrile and 3.90 ml
(14.50 mmol) of tri-n-butyltin hydride and heated to
reflux for 15 min. After cooling, the reaction mixture
wa~ concentrated to dryness in vacuo and the residue was
filtered on 60 g of silica gel (toluene : ethyl acetate
1:1). 494 mg (62 % of theory) of a mixture of 1-(5-O-
benzoyl-2- and -3-deoxy-~-D-ribofuranosyl)-5-trifluoro-
methyluracil were obtained as a colourless powder.
R~ - 0.46 (ethyl acetate)
IR (KBr): v = 3393, 3062, 1720, 1677, 1482, 1282, 1122,
1056, 710 cm~l
Thi~ product was di~olved in 17 ml of anhydrous aceto-
nitrile, treated with 429 mg (2.40 mmol) of l,l'-thiocar-
bonyldiimidazole and stirred at room temperature for
20 h. ~he solvent was evaporated in vacuo and the re~idue
was chromatographed on 44 g of ~ilica gel (toluene s
ethyl acetate lsl). 417 mg (68 % of theory) of the
Le A 28 306 - 65 -
,. ' .......................... . : :
- '' -
6~ 6
corresponding thiocarbonylimidazolide were obtained as a
colourless foam.
Rf = 0.35 (ethyl acetate)
MS (FAB) m/e = 511 (M+~)+
IR (KBr): v = 1700, 1468, 1394, 1338, 1279, 1189, 1115,
1040, 970, 752, 710 cm~1
This product was suspended in 3 ml of anhydrous toluene,
treated with 4 mg (0.02 mmol) of ~ azoisobutyronitrile
and 293 ~l (l.09 mmol) of tri-n-butyltin hydride and
heated to reflux for 30 min. After cooling, the solvent
was evaporated in vacuo and the re~idue was chromato-
graphed on 250 g of silica gel (toluene : ethyl acetate
1:1). 262 mg (85 % of theory) of the title compound were
obtained as a colourless foam. The physical data were
identical with those of the compound obtained according
to Method A.
Example 14
2',3'-Dideoxy-5'-0-(4-methylbenzoyl)-5-(trifluoromethyl)-
uridine
~ CF3
H3C ~ 00 N
Le A 28 306 - 66 -
2~ 9~6
A suspension of 347 mg (0.66 mmol) of the compound from
Example VI in 15 ml of anhydrous toluene was treated with
14 mg (0.09 mmol) of ~ azoisobutyronitrile and 1.30 ml
(4.80 mmol) of tri-n-butyltin hydride and heated to
S reflux for 30 min. After cooling, the reaction mixture
was concentrated to dryness in vacuo and the residue was
filtered on 20 g of silica gel ~toluene : ethyl acetate
3:2). 243 mg (70 ~ of theory) of the title compound were
obtained as a colourless foam.
R, = 0.30 (toluene : ethyl acetate 3:2)
IR (KBr): v = 3422, 1720, 1466, 1281, 1123, 753, 616 cm~
MS (FAB) m/e = 399 (M+H)+~
Le A 28 306 - 67 -
''
