BACKGROUND OF THE INVENTION
[0001] The present invention involves novel di-and tri- substituted thiazoles having pharmaceutical
activity as β-adrenergic blocking agent.
[0002] Thiazoles having an aminohydroxypropoxy substituent in the 2-position with or without
a specific additional substituent in the 4 or 5- position, are known and are taught
to have β-adrenergic stimulating activity (U.S. 3,850,945). Thiazoles having an aminohydroxypropoxy
substituent in the 4 or 5-position with no additional substitution are also known
and are taught to have β-adrenergic stimulating activity (U.S. 3,850,947, U.S. 3,850,946).
Thiazoles having the aminohydroxypropoxy substituent in the 2-position with an aminocarbonyl,
formamido, substituted oxycarbonyl amino group in the 4 or 5-position, are known and
taught to have S-adrenergic blocking activity (U.S.3,897,411). Thiazoles having the
following formula
are known and are taught to be β-adrenergic blocking agents. (U.S. 3,897,442). Thiazoles
of the formula
are known and are taught to block β-adrenergic receptors (U.S. 3,932,400).
[0003] Novel di- and tri-substituted thiazoles having a 4(3-amino-2-OR-propoxy) substituent
have been discovered. The thiazoles are active as β-adrenergic blocking agents.
Summary of the Invention
[0004] Di- and tri- substituted thiazoles having a 4(3-amino-2-OR-propoxy) group and their
pharmaceutical use.
Description of the Preferred Embodiments
[0005] An embodiment of the present invention is compounds having the formula
and pharmaceutically acceptable salts thereof wherein
R is hydrogen or C2-C12acyl,
R1 is C1-C12alkyl,
R2 is hydrogen, CF3', C6-C12 carbocyclic aryl, 6-membered-N-heteroaryl, Cl-C6 alkyl, C1-C6 alkylthio, C1-C6 alkylsulfinyl, Cl-C6 alkylsulfonyl, thienyl and furfuryl,
R3 is C1-C6 alkyl, -COOC1-C6 alkyl, COOC6-C12 aryl, cyano C6-C12 carbocyclic aryl, CF3 or -C-NR4R5 wherein R4 and R5 are independently selected from H and C1-C6 alkyl or are joined forming
provided that when R2 is phenyl, R3 is other than Cl-C6 alkyl or COOC1-C6 alkyl.
[0006] The pharmaceutically acceptable salts are the acid addition salts of the formula
I free base. Suitable acids include organic as well as inorganic acids. Examples of
useful organic acids are carboxylic acids such as acetic acid, pamoic acid, maleic
acid, succinic acid, citric acid, tartaric acid, oxalic acid, malic acid, pivalic
acid, heptanoic acid, lauric acid, propanoic acid, pelargonic acid, oleic acid and
the like, and non-carboxylic acids such as isethionic acid. Examples of useful inorganic
acids are the hydrogen halides i.e., HC1, HBr, HI, phosphoric acid, sulfuric acid,
and the like. The hydrohalide salts especially the hydro- cylorides and maleic acids,
especially the hydrogen maleate, are preferred.
[0007] R may be hydrogen or C
2-C
12 acyl. The C
2-C
12 acyl groups include alkanoyl groups such as acetyl, pivaloyl, dodecanoyl, hexanoyl,
succinoyl and the like - and carbocyclic aroyl groups such as benzoyl, 1- or 2- naphthoyl,
p-methylbenzoyl, p-phenylbenzoyl and the like. The C
2-C
6 alkanoyl and benzoyl groups are preferred acyl groups. Hydrogen is a most.prdferred
R group.
[0008] The R
1 substituent includes C
1-C
12alkyl, groups and preferably the C
l-C
6alkyl groups. The alkyl groups are exemplified by methyl, C
12H
25, hexyl, 2-ethylhexyl, isopropyl, sec-butyl, heptyl and the like. The C
3-4 branched chain alkyl R
1 groups are more preferred, with t-butyl being a most preferred group.
[0009] R
2 includes H, CF
3, C
6-C
12 carbocyclic aryl such as phenyl, monosubstituted phenyl e.g. p-tolyl, o-halophenyl,
p-nitrophenyl, p-methoxyphenyl and p-halophenyl; indanyl; 1- or 2-naphthyl and the
like, 6-membered-N-heteroaryl such as 2-, 3- or 4-pyridyl, pyridazinyl, pyrazinyl,
pyrimidinyl and the like; thienyl, furfuryl, C
1-C
6alkyl, e.g. methyl, n-hexyl, isopropyl,sec-butyl, ethyl and the like, C
1-C
6 alkylthio, and the sulfinyl and sulfonyl derivatives exemplified by C
2H
5-S, C
4H
9-SO, C
6-H
13-SO
2, CH(CH
3)
2, CH3-SO, t-butyl-S and the like. Preferred R
2 groups are hydrogen, C
1-C
6alkyl and C
1-C
6alkylthio, especially CH
3-S.
[0010] The R
3 substituent includes CF
3, C
1-C
6 alkyl, CN, C
6-C
12 carbocyclic aryl such as phenyl, carboxylic acid esters and amides. The C
1-C
6 alkyl group is exemplified by CH
3, isopropyl, and the like. The ester grup is C
1-C
6 alkylester exemplified by -COOCH
3, -COOC
6H
13, -COOCH(CH
3)
2, -COOC
2H
5 and the like and C
6-C
12 arylester, preferably carbocyclic aryl, exemplified by C
6H
5-OOC, p-CH
3-C
6H
4-OOC-, p-C
6H
5-C
6H
4-OOC-, C
9H
9-OOC- and the like. The amide group includes -CONH
2, C
l-C
6 substituted amide groups such as -CON(CH
3)
2, -CON(C
6H
13)
2, -CONHC
2H
5, -CON (sec. butyl)
2 and the like and carbonyl heterocyclic groups such as
of the R
3 groups, CN, CF
3 and amide, especially CONH
2, are preferred.
[0011] The formula I compounds have a chiral center (at the 2 carbon in the propoxy substituent)
which confers optical activity. The optical isomers are designated conventionally
as L and D, 1 and d, + and -, S and R or by combinations of these symbols. Where the
formula or compound name herein carries no specific designation, the formula or name
includes the individuvl isomers, the mixtures thereof and racemates.
[0012] The thiazole compounds which are preferred have the formula
Formula II compounds where R
2 is H, C
1-C
6 alkylthio, preferably CH
3-S-, or said heteroaryl groups, especially pyridyl, R
3 is CN, CF
3, amide, C
1-C
6 alkyl or said ester group and R
1 is C
l-C
6 alkyl especially C
3-C
4 branched alkyl are more preferred. In most preferred formula II compounds, R
2 is said alkylthio or heteroaryl, R
3 is CN, CF
3, CONH
2, C
l-C
6alkyl or said ester and R
1 is C
3-C
4 branched alkyl.
[0013] Another preferred group of thiazoles has the formula
where R
2 is H, C
1-C
6 alkyl, C
1-C
6 alkylthio or pyridyl, R
3 is CN, CF
3, C
l-C
6 alkyl or CONH. In more preferred formula III thiazoles, said branched alkyl is tert.-butyl,
R
2 is H, CH
3, CH
3S or pyridyl, and R
3 is CN, CH
3, CONH
2 or CF
3 and the thiazoles where said branched alkyl is tert.-butyl, R
2 is H, CH
3S or pyridyl and R
3 is CN or CONH
2 are partic- cularly preferred.
[0014] Of the optical isomers those having the S-isomer configuration are preferred.
[0015] The thiazoles of the present invention have β-adrenergic blocking activity. This
was determined in an in-vivo test using dogs as the test animals. In this test, representative
thiazole compounds, were found to counteract the a-adrenergic stimulating effect of
isoproterenol.
[0016] Certain of the present thiazoles also exhibit an antihypertensive effect of immediate
onset when administered to a spontaneously hypertensive (SH) rat. Representative of
such compounds are those having the formula
and
[0017] The present thiazoles also show random vasodilator activity.
[0018] The present thiazole compounds will effect β-adrenergic blockade in humans. This
β-adrenergic blocking effect is useful in the therapeutic treatment of various cardiovascular
conditions such as angina pectoris, arrhythmia etc. In administering these formula
I compounds for their P-adrenergic blocking effect, the daily dosage may range from
about 1.5 mg. to about 3000 mg. Preferred daily dosages are about 6.5 mg. to about
200 mg. Conventional dosage forms suitable for oral as well as parenteral, e.g. intravenous,
intraperitoneal etc., administration are used. Oral dosage forms include tablets,
capsules, troches, liquid formulations e.g. solutions, emulsions, elixirs, etc. -
parenteral dosage forms include liquid formulations especially solutions. The compositions
are prepared using conventional procedures and compounding ingredients such as starch,
sterile water, flavoring additivies, antioxidants, binders, vegetable oils, sweetening
agents, glycerine and the like.
[0019] Thiazoles which exhibit the immediate onset antihypertensive activity are useful
for treating hypertensive humans at daily dosages ranging from about 100 to about
3000 mg. administered in oral or parenteral dosage forms.
[0020] The present thiazoles can be prepared by any convenient process.
[0021] One such process involves the coupling of a suitably substituted thiazole with a
suitably substituted oxazolidine and hydrolyzing the reaction product obtained. This
process is illustrated by the following set of reaction equations:
Z is an alkyl or arylsulfonyl group. Examples of sulfonyl groups are CH
3-SO
2-, C
6H
5-SO
2-, NO
2-C
6H
4SO
2-, p-CH
3-C
6H
4-SO
2-, mesitylene-SO
2-, CH
3O-C
6H
4-SO
2-, trichlorobenzene-SO
2-, C
16H
33-SO
2- and the like. Suitable bases are alkali metal bases such as K
2CO
3, K-O-C(CH
3)
3, NaH, organolithiums e.g. phenyllithium, n-butyllithium, lithium diisopropyl amide
and the like.
[0022] R
6 is hydrogen or other C
1-C
12 alkyl or C
6-C
12 carbocyclic aryl residue of any suitable v aldehyde
Examples of suitable aldehydes are the aryl aldehydes such as benzaldehyde, naphthaldehyde
4-phenylbenzaldehyde, furfural, bromobenzaldehyde, tolualdehyde, mesitaldehyde and
the like, or an alkanal such as acetaldehyde, butyraldehyde,
and the like. The process for preparing oxazolidines where Z is hydrogen (and a related
coupling reaction) is disclosed in U.S. 3,718,647 and U.S. 3,657,237 and to the extent
necessary the pertinent disclosure is incorporated herein by reference.
[0023] The coupling reaction can be carried out at temperatures ranging from about 0°C.
to about 130°C. A temperature range of about 50°C. to about 130°C is preferred. The
reaction is generally carried out in a solvent. Any suitable solvent may be used.
Examples of useful solvents are dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide,
tert. butanol, dioxane, toluene, acetone and the like. The hydrolysis is carried out
using a conventional acid system e.g. by treatment with a solution of any suitable
acid such as HC1, H
2S0
4, CH
3COOH and the like. The hydrolysis product can be directly obtained as the salt of
the acid used for the hydrolysis. Ordinarily, the product IA is recovered as the free
base after conventional neutralization of the salt.
[0024] The coupling reaction is ordinarily carried out at atmospheric pressure. Higher pressures
may be used if desired.
[0025] When a racemic oxazolidine (formula V) is used as a reactant, the product is obtained
as a racemate. The racemate may be separated into its individual enantiomers by conventional
resolution techniques.
[0026] When R
6 in the oxazolidine (e.g. formula V or VI) is other than hydrogen, in addition to
the chiral center at oxazolidine position 5 there is a second chiral center at position
2. However, whenever an oxazolidine is designated e.g. as (S), (R) or (R,S), this
designation refers only to the optical configuration around the carbon atom at the
5 position.
[0027] By using a single optical isomer of the formula V oxazolidine in the above reaction
the thiazole product (IA) may be obtained directly as a single enantiomer. This provides
a convenient way for directly preparing individual isomers of the present thiazoles.
[0028] Thiazoles represented by formula I wherein R is other than hydrogen are conveniently
prepared by treating the corresponding thiazole where R is hydrogen with an appropriate
acylating agent such as an acyl halide, e.g. undecanoyl chloride, pivaloyl chloride,
benzoylchloride, p-methoxybenzoyl chloride, an anhydride e.g. acetic anhydride and
the like. The reaction is illustrated by the following equation:
[0029] The compounds of the present invention also include the pharmaceutically acceptable
salts of the novel thiazoles. These salts are conveniently prepared e.g. by treating
the thiazole with an appropriate amount of a useful acid, generally in a suitable
solvent.
[0030] Additional processes for preparing thiazoles with certain other substituents are
illustrated by the following equation sequences. Conventional reaction conditions
are employed. The symbol L represents the -CH
2-CHOR-CH
2-NR
1 group.
[0031] The thiazoles having an alkylsulfinyl or alkylsulfonyl substituent are prepared by
oxidizing the corresponding C
1-C
6 alkylthio containing compound. Any suitable oxidizing agent, e.g. H
20
2, may be used. The following equation illustrates the reaction
[0032] The 4-OH substituted thiazole intermediates used in the oxazolidine coupling reaction
described above are prepared using conventional processes illustrated by the following
equations:
[0033] The following examples illustrate preparation of representative thiazoles of the
present invention. All temperatures are in °C.
EXAMPLE 1
(S) 5-Methyl-2-phenyl-4(3-tert. butylamino-2-hydroxypropoxy) thiazole hydrogen maleate
salt
[0034] To a stirred solution of (S) 2-phenyl-3-tert.butylamino-5-hydroxymethyloxazolidine
(2.5 g., 0.01m) and dry pyridine (5 ml.) is added portionwise p-toluenesulfonyl chloride
(2.0 g., 0.011 m), while maintaining the temperature of the reaction below 30°C. After
the addition, the mixture is stirred at room temperature for 3 hours. To the solid
mixture is added a solution of K
2C0
3 (1.4g., 0.01 m) in H
20 (10 ml.) and the solution extracted with CHC1
3 (3 x 25 ml.). The organic layer is dried over Na
2SO
4, filtered and concentrated to dryness below 50°C to yield the tosylate of (S) 2-phenyl-3-tert.
butyl- amino-2-hydroxymethyloxazolidine which is used in the next step without further
purification.
[0035] Into a dry flask under N
2 is added 4-hydroxy-5-methyl-2-phenylthiazole (1.91 g., 0.1 m), dimethylformamide
(DMF) (20 ml.) and NaH (50% mineral oil, 0.5 g., 0.01 m). After stirring at room temperature
for 15 minutes, the tosylate of (S) 2-phenyl-3-tert.-butylamino-5-hydroxymethyl- oxazolidine
(0.01 m in DMF (20 ml.) is added and the solution heated under reflux with stirring.
After 12 hours, the solvent is removed under reduced pressure (1.5 mm). The residue
is treated with IN HC1 (100 ml.) and heated on a steam bath for 3/4 hours. After cooling,
the aqueous layer is extracted with ether (2 x 50 ml.), neutralized with saturated
Na
2CO
3, and extracted with CHC1
3 (3 x 100 ml.). The organic layer is dried over Na
2SO
4, filtered and concentrated to dryness. The residue is chromatographed on silica gel
60 and the product eluted with 10% MeOH-CHC1
3. The crude product is crystalized with maleic acid in isopropanol (IPA)-MeOH to yield
0.25 g. (6%) of 5-methyl-2-phenyl-4(3-tert.butyl - amino-2-hydroxypropoxy) thiazole
hydrogen maleate salt, m.p. 174-6°C.
EXAMPLE 2
(S) 5-Carbamoyl-2-phenyl-4-(3-tert.butylamino-2-hydroxypropoxy) thiazole hydrogen
maleate salt.
[0036] A. Into a dry flask under N
2 is added ethyl 4-hydroxy-2-phenylthiazole-5-carboxylate (2.5 g., 0.01 m), DMF (20
ml.) and NaH (50% mineral oil, 0.5 g., 0.01 m). After stirring for 15 minutes, a solution
of the tosylate of (S) 2-phenyl-3-tert.-butylamino-5-hydroxymethyloxazolidine (0.01
m) in DMF (15 ml.) is added at 0-4°C. and the solution heated with stirring at 100°C.
After 15 hours, the solution is cooled to 0-10°C., poured into H
20 (100 ml.) and extracted with ether (3 x 100 ml.). The organic layer is extracted
with IN HC1 (2 x 50 ml.) and the acid layer added to NaOAc (8.2 g., 0.1 m). After
5 hours, the solution is extracted with ether (2 x 50 ml.). The aqueous layer is neutralized
with saturated Na
2C0
3 and extracted with CHCl3 (3 x 100 ml.). The organic layer is dried over Na
2SO
4, filtered and concentrated to dryness. The residue is chromatographed on alumina
(activity grade II, E. Merck) and the product eluted with 25% hexane - CHC1
3. The crude product is crystallized with maleic acid in CH
3CN - ether to yield 0.7 g. (14%) of (S) ethyl-2-phenyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole-5-carboxylate
hydrogen maleate, m.p. 165-7°C.
[0037] B. A mixture of (S) ethyl-2-phenyl-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole-5-carboxylate,
obtained by neutralizing the product from A., (4.7 g., 0.012 m), MeOH (90 ml.) and
liquid NH
3 (22 g.) is heated at 100°C. in a sealed tube. After 24 hours, the reaction mixture
is concentrated to dryness. The residue is chromatographed on alumina (activity grade
II, E. Merck) and the product eluted with CHC1
3. The crude product is crystallized with maleic acid in IPA to yield 1.65 g. (30%)
of (S) 5-carbamoyl-2-phenyl-4-(3-tert.butylamino-2 hydroxypropoxy) thiazole hydrogen
maleate salt, m.p. 184-5°C.
EXAMPLE 3
(S) 5-Cyano-2-phenyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole hydrogen maleate
salt hemihydrate
[0038] To triphenylphosphine oxide (2.25 g., 0.008 m) in CH
2C1
2 (20 ml.) is added dropwise at 0-4°C. a solution of triflic anhydride (1.4 g., 0.0089
m) in CH
2Cl
2 (15 ml.). After 15 minutes, (S) 5-carbamoyl-2-phenyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole
(1.4 g., 0.004 m) is added and the solution allowed to warm to room temperature. After
stirring overnight at room temperature, the mixture is poured into saturated Na
2CO
3 (100 ml.) and the solution extracted with CH
2C1
2 (3 x 400 ml.). The organic layer is dried over Na
2SO
4, filtered and concentrated to dryness. The residue is chromatographed an alumina
(activity grade II, E. Merck) and the product eluted with CHC1
3. The crude product is crystallized with maleic acid in IPA to yield 0.3 g. (16%)
of (S) 5-cyano-2-phenyl-4-(3-tert.-butylamino-2-hydroxypropoxy)thiazole hydrogen maleate
salt hemihydrate, m.p. 204-6°C.
EXAMPLE 4
(S) Ethyl-2-methylthio-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole-5-carboxylate
hydrogen maleate salt
[0039] Into a dry flask under N
2 is added ethyl-4-hydroxy-2-methylthiazole-5-carboxylate (20 g., 0.091 m), DMF (200
ml.) and NaH (50% mineral oil, 5.0 g., 0.104 m). After stirring for 15 minutes, a
solution of the tosylate of (S)-2-phenyl-3-tert.butylamino-5-hydroxymethyloxazolidine
(0.106 m) in DMF (150 ml.) is added at room temperature and the solution heated on
a steam bath with stirring. After 15 hours, the solution is cooled to 0-10°C., poured
into H
20 (1 1.) and extracted with ether (3 x 300 ml.). The organic layer is washed with
H
20 (2 x 150 ml.) and IN HC1 (3 x 233 ml.). The acid layer is added to NaOAc. 3H
20 (95 g., 0.7 m). After 5 hours, the solution is extracted with ether (2 x 200 ml.).,
neutralized with saturated Na
2CO
3 and extracted with CHC1
3 (3 x 300 ml.). The organic layer is dried over Na
2SO
4, filtered and concentrated to dryness. The residue is chromatographed on alumina
(activity grade II, E. Merck) and the product eluted with CHC1
3. The crude product is crystallized with maleic acid in IPA-Et20 to yield 8.8 g. (21%)
of (S) ethyl 2-methylthio-4-(3-tert.butylamino-2-hydroxypropoxy)-thiazole-5-carboxylate
hydrogen maleate salt, m.p. 114-116°C.
EXAMPLE 5
(S) 5-Carbamoyl-2-methylthio-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole hydrogen
maleate salt
[0040] Using the same procedure described in Example 2B (S) ethyl 2-methylthio-4-(3-tert.butyl-
amino-2-hydroxypropoxy)thiazole-5-carboxylate (5.2 g., 0.015 m) MeOH (90 ml.) and
liquid ammonia (33 g.) are heated to yield 0.9 g. (14%) of (S) 5-carbamoyl-2-methylthio-4-(3-tert.butylamino-2-hydroxypropoxy)-thiazole
hydrogen maleate salt, m.p. 180-2°C.
EXAMPLE 6
5 Carbamoyl-2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole hydrogen maleate
salt hemihydrate
[0041] A. Using the procedure of Example 2A, ethyl 4-hydroxy-2-methylthiazole-5-carboxylate
(9.35 g., 0.05 m),
DMF (100 ml.), NaH (57% mineral oil, 2.5 g., 0.052 m) and the tosylate of 2-phenyl-3-tert.butyl-
amino-2-hydroxymethyloxazolidine (0.053 m) in DMF (100 ml.) are reacted to yield 4.7
g. (30%) of ethyl 2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole-5-carboxylate.
[0042] B. Using the procedure of Exmaple 2B, ethyl 2-methyl-4(3-tert.-butylamino-2-hydroxypropoxy)-thiazole-5-carboxylate
(4 g., 0.014 m), MeOH (90 ml.) and liquid NH
3 (33 g.) are heated to yield 1.3 g. (22%) of 5-carbamoyl-2-methyl-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole
hydrogen maleate salt hemihydrate, m.p. 177-78°C.
EXAMPLE 7
5 Carbamoyl-2-methyl-4-(3.-tert.butylamino-2-hydroxypropoxy)thiazole hydrogen maleate
salt hemihydrate
[0043] A. Using the procedure of Example 2A, ethyl 4-hydroxy-2-methylthiazole-5-carboxylate
(28 g., 0.15 m), DMF (500 ml.), NaH (50% mineral oil, 7.5 g., 0.16 m) and the tosylate
of (S) 2-phenyl-3-tert.-butylamino-5-hydroxymethyloxazolidine (0.15 m) in DMF (100
ml.) are reacted to yield 9.8 g. (20%) of (S) ethyl 2-methyl-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole-5-carboxylate.
[0044] B. Using the procedure described in Example 2B, (S) ethyl 2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)-thiazole-5-carboxylate
(9.8 g., 0.034 m), methanol (185 ml.) and liquid NH
3 (8.5 g.) are heated to yield 3.6 g. (29%) of (S) 5-carbamoyl-2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole
hydrogen maleate salt, m.p. 161-163°C.
EXAMPLE 8
(S) 5-Cyano-2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole hydrogen maleate
salt.
[0045] Using the procedure described in Example 3, triphenylphosphine oxide (2.78 g., 0.01
m) in CH
2C1
2 (20 ml.), and (S) 5-carbamoyl-2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole
(1.4 g., 0.005 m) are reacted to yield 0.9 g. (47% of (S) 5-cyano-2-methyl-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole
hydrogen maleate salt, m.p. 172-174°C.
EXAMPLE 9
(S) 5-Methyl-2-(4'-pyridyl)-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole.
[0046] Using the procedure in Exmaple 2A, 4-hydoxy-5-methyl-2-(4'-pyridyl)thiazole (3.65
g., 0.019 m), DMF (50 ml.), NaH (57% mineral oil, 0.95 g., 0.02 m) and the tosylate
of (S) 2-phenyl-3-tert.butylamino-5-hydroxymethyloxazolidine (0.02 m) in DMF (20 ml.)
are reacted to yield 0.6 g. (10%) of (S) 5-methyl-2-(4'-pyridyl)-4-(3-tert. butylamino-2-hydroxypropoxy)-thiazole,
m.p. 102-104.
EXAMPLE 10
(S) Ethyl 4-(3-tert.butylamino-2-hydroxypropoxy)-thiazole-5-carboxylate hydrogen maleate
salt
hemihydrate
[0047] To a solution of (S) ethyl 2-methylthio-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole-5-carboxylate
(3.6 g., 0.01 m) in 3N HC1 (20 ml.) is added portionwise with stirring zinc dust (2.6
g.). After 3.5 hours at room temperature, the mixture is poured into saturated Na
2CO
3. The suspension if filtered and the filter pad washed wll with CHC1
3. The aqueous layer is extracted with CHC1
3 (3 x 75 ml.). The combined CHC1
3 extracts are dried over Na
2SO
4, filtered and concentrated to dryness. The residue is chromatographed on silica gel
and the product eluted with CHCl
3 saturated with aqueous ammonia. The crude product is crystallized with maleic acid
in EtOH-Et
20 to yield 0.4 g. (9%) of (S) ethyl 4-(3-tert. butylamino-2-hydroxypropoxy)-thiazole-5carboxylate
hydrogen maleate salt hemihydrate, m.p. 103-105°C.
EXAMPLE 11
(S) 5-Carbamoyl-4-(3-tert.butylamino-2-hydroxypro- poxy)thiazole
[0048] Using the procedure described in Example 10, (S) 5-carbamoyl-2-methylthio-4-(3-tert.butyl-
amino-2-hydroxypropoxy)thiazole (1.7 g., 0.005 m), 3N HC1 (10 ml.) and zinc dust (0.94
g.) are reacted. Extraction of the aqueous layer with ether yielded unreacted starting
material while extraction next with CHC1
3 yielded 0.7 g. (48%) of 5-carbamoyl-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole.
EXAMPLE 12
(S) 5-Cyano-4-(3-tert.butylamino-2-hydroxypropoxy)-thiazole hydrogen maleate salt
[0049] Using the procedure described in Example 3, triphenylphosphine oxide (1.42 g., 0.005m)
in CH
2C1
2 (10 ml.), triflic anhydride (0.78 ml., 0.005 m) in CH
2C1
2 (10 ml.) and (S) 5-carbamoyl-4-(3-tert. butylamino-2-hydroxypropoxy)thiazole (0.7
g., 0.0026 m) are reacted to yield 0.18 g. (19%) of (S) 5-cyano-4-(3-tert.butylamino-2-hydroxypropoxy)thiazole
hydrogen maleate salt, m.p. 168-170°C.
[0050] Claims to the invention follow.