DK142175B - METHOD OF ANALOGY FOR THE PREPARATION OF THIAZOLO- OR 1,3,4-THIADIAZOLO- (3,2-) - PYRIMIDIN7-ON-5-CARBOXYLIC ACID DERIVATIVES - Google Patents

Description

OD PUBLICATION PUBLICATION 142175 few) \ fia / DENMARK (51) lnt CI · c 07 D B, 3 / 0i § (21) Application No. 2475/77 (22) Filed on 3 · jUTl. 1977 (24) Life Day 3 · JUH · 1977 (44) The claim submitted and 1 nQn

the presenting amendment published on P «eP · * yOU

DIRECTORATE OF

PATENT AND TRADEMARKET SYSTEM (30) Priority requested by the ct

Jun 4 1976, 2625117a DE

(71) GRUENENTHAL GMBH, Fostfach 129, 5190 Stolberg, DE.

(72) Inventor: Siegfried Herr ling, 33 Dohlenweg, D-5190 Stolberg, DE.

(74) Plenipotentiary 'proceedings:

International Patent Office.

(54) Analogous procedure for further thiazolo- or 1,3,4-thi = adiazolo- (5,2-a) -pyrimidine-7-one-5-c ar boxylic acid in water.

The invention relates to an analogous process for the preparation of novel thiazolo or 1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid derivatives of the general formula I, wherein X 2 is a nitrogen atom or the group R - C 2, R is hydrogen, a pharmaceutically useful cation or an alkyl group having 1 to 5 carbon atoms,

12 1 R and R are the same or different and - with the proviso that R

2 cannot be hydrogen at the same time that R is hydrogen or methyl and X cannot be nitrogen at the same time as R 1 is methyl-stands for hydrogen, alkyl groups having 1 to 5 carbon atoms or phenyl, benzyl, phenylethyl, thienyl or pyridyl groups optionally substituted with 1 to 3 halogen atoms, alkyl or alkoxy groups having up to 4 carbon atoms in the alkyl group, or 2 142176 eyeloalkyl groups having 5 to 7 carbon atoms, or pharmaceutically useful salts of these compounds.

Surprisingly, it has been found that the compounds of formula I

causes a pronounced stimulation of the iiranun system and because of this property are valuable therapeutics for such diseases in which an increase in the body's own defense forces is desirable, especially when the immune system of the diseased organism is damaged or insufficiently developed. Such diseases, which can be treated with the drugs herein, are e.g. viral infections, bacterial infections, systemic lupus erythematosus / tumors, also for the prevention of metastasis.

The immunostimulatory effect was shown experimentally as follows: a) In vitro phagocytosis study:

Groups of each 20 mice were orally administered 1, 5, 10 and 15 mg of 3-phenyl-7H-thiazolo- [3,2a] -pyrimidin-7-one-5-carboxylic acid ethyl ester (orally) for 5 days, respectively. hereinafter referred to as "substance A") per kg body weight. They, together with 20 untreated control animals, were then sacrificed and, using tissue culture media, the peritoneal macrophages or polymorphic nucleated leucocytes were flushed out of the abdominal cavity. The cells were washed and set in the individual samples at the same number per day. volume and either incubated with latex particles or with pathogenic staphylococci for 1, 2 and 3 hours. The cells are then washed again, transferred to slides and stained. The phagocytosis index is determined by counting the cells loaded with latex particles or with staphylococci relative to the free cells.

Substance A can also be injected intraperitoneally into the test animals 1 hour before the start of the trial in the various doses and then proceed as described above.

In this way, too, a remarkable increase in phagocytosis is achieved upon administration of substance A, with values of up to approx. 150% of phagocytosis indices obtained on cells of untreated control animals.

b) Study of phagocytosis in vivo:

As described in (a), groups of every 20 mice were pretreated with substance A. Three days after completion of substance administration, the test animals were then injected intraperitoneally with latex particles or staphylococci. The animals were then sacrificed in appropriate subgroups 1, 2, and 3 hours after injection of these phagocytic particles. The peritoneal cells were removed, washed, applied to slides by the cytocentrifuge and then stained. In determining phagocytic synthesis, the phagocytosis-stimulating influence of substance A was also confirmed by this method.

Similar results were also obtained when substituting other compounds of formula I, such as e.g. 2-methyl-3-phenyl-7H-thiazolo- [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester, 3- (p-tolyl) -7H-thiazolo- [3,2-a ] -pyrimidin-7-one-5-carboxylic acid ethyl ester or 2-methyl-3- (p-bromophenyl) -7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester.

c) Stimulation of immune-gluboline G receptor activity on the macrophage surfaces.

Groups of 18 to 20 g of heavy female mice were subcutaneously administered either 0.1 or 1 or 10 mg of the substance to be tested per kg body weight at one time. After 24 hours, the animals were sacrificed and the peritoneal macrophages flushed out of the abdominal cavity using a cell culture medium containing 10% calf serum, adjusted to a density of 10® cells / ml, in volumes of each 3 ml led to petri dishes (diameter 5 cm). and incubated at 27 ° C for 4 hours in hatch.

The cells not adhering to the glass were gently washed by cell culture medium. Then, to each petri dish, 3 ml of a 0.1% suspension of human blood type A ^ erythrocytes was added. [These erythrocytes were pre-incubated 30 minutes (with cell culture medium diluted 1:50) with serum from 80 days old female mice. C 57 BL / 10 at room temperature, whereby they were loaded with the specific "natural" antibodies that C 57 BL / 10 female mice form]. The macrophages adhering to the petri dishes, depending on the immune globulin G receptor activity, bind to their surface the human pre-treated erythrocytes to varying degrees.

It was found that the macrophages from the substances of formula I pretreated animals bind significantly more (antibody-loaded) erythrocytes than the macrophages from untreated animals, the differences often amounting to several hundred percent.

To demonstrate the effects against viral infections, mice were infected with Hepatitis viruses (from mice). Then, when orally 24 hours later, a single dose of the test substance was administered orally at the dose given in the following table, the animals survived in the percentage also indicated in the table, while 80-100% of the untreated infected control animals died: 2 rr XR Dose% Survivor (mg / kg) Animal C * H E2 - £ - 0.5 60 - 70

CjH5 CH3 R2-C- 0.5 60 c2h5 h r2-c- οη3- <Τ ^ - 50 C2H5 H j E2-f (- C2H5-0> "1.0 i 60 i: COHc CH-, I R2 -C- Br- / V »0.1 '50 2 5 3 I II I \ = / CH3 η IN j - 0.1 j 60 i O. N 0.5 50-60 ---- 1 -i._ ^^ _ I_

These test results show the surprising therapeutic value of the compounds of formula I, especially for the therapy of viral infections.

The process of the invention is characterized by condensing a compound of formula II as claimed in claim 1 wherein R 1 and X have the same meaning as above with an acetylene dicarboxylic acid ester derived from an alkanol containing 1 to 5 carbon atoms in the presence of a solvent or suspension agent, optionally at elevated temperature, preferably excluding light and / or air, and then optionally by hydrolysis converting the group R to a hydrogen atom and / or transferring the obtained compounds into pharmaceutically useful salts.

If the group -COOR in a compound of formula I is to represent a carboxyl group or a salt derived therefrom, but R represents an alkyl group of 1 to 5 carbon atoms, it is readily possible to hydrolyze the ester group then present and optionally transfer the resulting compound with the formula I with free carboxylic acid group in pharmaceutically useful salts by reaction with suitable bases. In particular, such salts are the alkali metal, alkaline earth metal and ammonium salts of the compounds of formula I.

5 142175

Especially when R represents an alkyl group of 1-5 carbon atoms, the compounds of formula I are capable of forming salts with acid. Such pharmaceutically useful salts are e.g. the formates, acetates, propionates, hydrochlorides, hydrobrarides, sulfates or phosphates.

The reaction between the compound of formula II and the acetylenedicarboxylic acid ester takes place in the presence of a solvent or suspension agent, optionally at elevated temperature. Suitable solvents or suspending agents are e.g. lower aliphatic alcohols, especially methanol, ethanol and propanols, acetic acid ethyl or propyl esters, acetonitrile, tetrahydrofuran, dioxane, chlorobenzene or also dimethylformamide. If at least one of the groups R and R represents a pyridyl group, the condensation is suitably carried out in the presence of at least 1 mole of an acid, preferably acetic acid. The formation of resin-like and dark by-products is largely avoided by working under the exclusion of light and air. Conveniently, one can also proceed such that one first reacts to the reaction partner e.g. in ethanol and then by heating in a higher boiling solvent, e.g. chlorobenzene, completes the cyclization.

U.S. Patent No. 3,813,360 already discloses certain 7β-thiazolo [3,2-a] pyrimidin-7-one derivatives, which are reported to have an anti-fungal effect, among others. However, a test of the anti-mycotic effect of the 3-methyl-5-carbomethoxy-7H-thiazolo [3,2-a] pyrimidin-7-one disclosed in this patent showed that this compound itself in concentrations of 100 µg / ml - had no effect on Aspergillus parasiticus, Candida albicans, Sporotichon Beurmannii or Trichophyton Gypseum. There is no disclosure in the patent about the immune stimulating effects of the compounds mentioned therein, and it is thus surprising that the compounds of formula I obtained according to the invention have the valuable properties described above.

I Journ. Heterocycl. Chem., Vol. 12 (1975) pages 675-681 describe, among other things, the preparation of 2-methyl-7H-1,3,4-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid and its methyl ester. It is also shown that this acid can be easily decarboxylated. However, there is no mention in this literature of biological properties or effects of these compounds.

The following examples further explain the preparation of the compounds. In the execution, no value was placed on obtaining optimal yields. All temperature indications are uncorrected.

6 142175

Example 1 17.6 g of 2-amino-4-phenylthiazole are dissolved in 100 ml of tetrahydrofuran, cooled to ca. 17.5 g of acetylenedicarboxylic acid diethyl ester are slowly added at this temperature with stirring. The mixture is allowed to stand for 3 days, the crystals formed are filtered off (the amount of which is increased by evaporation of the mother liquor to about half the volume) and recrystallized from ethanol. 3-Phenyl-7H-thiazolo [3,2-a] pyrimidin-7-one carboxylic acid ethyl ester is obtained in a yield of 16.9 g = 56.3% of theory. Mp: 173-175 ° C.

C15H12H2 ° 2S (300'34)

C Η N S

Calculated: 60.0% 4.03% 9.34% 10.6%

Found: 59.7% 4.30% 9.60% 10.5%.

Analogously, acetylene dicarboxylic acid dimethyl ester 3-phenyl-7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid methyl ester melting at 195-199 ° is obtained. C during decomposition.

Example 2

Proceed as in Example 1, however, using 19 g of 2-amino-4-phenyl-5-methylthiazole, thus obtaining the 2-methyl-3-phenyl-2-methyl-3-phenyl-melting crystallization after recrystallization from ethyl acetate. 7H-thiazolo [3,2-a] pyrimidin-7-one-carboxylic acid ethyl ester.

C16H14N2 ° 3S (314'3?)

C Η N

Calculated: 61.1% 4.49% 8.92%

Found: 60.7% 4.46% 8.61%.

Example 3

Proceed as in Example 1 but use instead of tetrahydrofuran ethanol as the solvent, displacing the air from the reaction vessel with nitrogen and storing the reaction mixture in the dark. Similarly, the product is obtained in substantially pure form in a yield of 86.4% of theory.

Example 4 9.5 g of 2-amino-4- (p-tolyl) -thiazole are reacted in 100 ml of tetrahydrofuran with 8.7 g of acetylenedicarboxylic acid diethyl ester in the manner described in Example 7. The reaction mixture is evaporated, the residue is dissolved x ethyl acetate and added to ligroin. There is obtained the 3- (p-tolyl) -7H-thiazolo- [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester having a melting point of 122-125 ° C (decomposition).

C16H14N2 ° 3S (314'37)

C Η N S

Calculated: 61.1% 4.49% 8.92% 10.18%

Found: 60.7% 4.60% 8.67% 9.87%.

Example 5

9.4 g of 2-amino-4- (p-bromophenyl) -5-methyl-thiazole and 5.95 g of acetylenedicarboxylic acid diethyl ester are obtained, thus obtaining 3- (p-bromophenyl) ) -7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester, mp 217-220 ° C (decomposition).

c16Hl3BrN2 ° 3S (393'27)

C Η N S

Calculated: 48.75% 3.33% 7.12% 8.13%

Found: 48.75% 3.30% 6.85% 8.02%.

Example 6

Reaction of 12.2 g of 2-amino-4- (2 ', 41-dichlorophenyl) -thiazole with 8.5 g of acetylenedicarboxylic acid diethyl ester in the presence of 150 ml of ethanol according to the procedure described in Example 3 gives the -192 ° C decomposing melting 3- (2 *, 4 * - dichlorophenyl) -7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester.

C Η N S

Calculated: 48.78% 2.72% 7.57% 8.67%

Found: 48.82% 2.75% 7.56% 8.53%.

Example 7 10 g of 2-amino-4- (4'-ethylphenyl) -thiazole are dissolved in 50 ml of ethanol and 8.4 g of acetylenedicarboxylic acid diethyl ester are added. Allow to stand overnight and then evaporate to dryness in vacuo at a bath temperature of 40-50 ° C. The residue is added to 50 ml of chlorobenzene and heated at reflux for 1 hour. After evaporation in vacuo, the residue is dissolved in ether, treated with charcoal and then petroleum ether added.

8 142175

The precipitated product is washed with a little ether and dried. There is thus obtained the 3- (4'-ethylphenyl) -7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester melting at 142-144 ° C.

C Η N S

Calculated: 62.17% 4.91% 8.53% 9.75%

Found: 62.04% 4.83% 8.26% 9.46%.

Example 8 8.5 g of 2-amino-4- (3 ', 4'-dimethoxyphenyl) -thiazole and 6.1 g of acetylenedicarboxylic acid diethyl ester are added to 100 ml of ethanol. After displacing the air in the reaction vessel by nitrogen, the mixture is heated to ca. 50 ° C until a clear solution is formed. This is evaporated to dryness in vacuo after 2 days standing at room temperature. The residue is washed with acetic acid ethyl ester and then with ether, then dried. The 3- (3 ', 4'-dimethoxyphenyl) -7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester thus obtained melts at 172-174 ° C with decomposition.

C12H16N2 ° 5S <360'4)

C Η N S

Calculated: 56.65% 4.47% 7.78% 8.88%

Found: 55.93% 4.84% 7.51% 8.80%.

Example 9

A mixture of 12.8 g of 2-amino-5-dimethylthiazole, 150 ml of ethanol and 17 g of acetylenedicarboxylic acid diethyl ester is heated to ca. 30 ° C, resulting in a slightly exothermic reaction. The mixture is left to stand overnight, then evaporated to dryness in vacuo and the residue is heated with 100 ml of chlorobenzene for 1 hour before boiling. After evaporation in vacuo, the residue is triturated with acetic acid ethyl ester, thereby crystallizing. The product is aspirated, washed with ether and dried. The 2,3-dimethyl-7H-thiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester thus obtained melts at 140-142 ° C.

C11H12N2 ° 3S (252'3>

C Η N S

Calculated: 52.35% 4.79% 11.09% 12.69%

Found: 52.43% 4.72% 10.97% 12.93%.

9 14217D

Example 10 10.1 g of 2-amino-1,3,4-thiadiazole are added to 100 ml of tetrahydrofuran and then slowly 14.2 g of acetylenedicarboxylic acid dimethyl ester.

The reaction mixture is allowed to stand for 3 days to form a clear yellow solution. This is evaporated in vacuo to dryness. Recrystallization of the residual acetic acid ethyl ester gives the melting 7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid methyl ester at 134 ° C.

C Η N S

Calculated: 39.80% 2.39% 19.90% 15.18%

Found: 39.70% 2.44% 19.66% 15.11%.

Example 11

A mixture of 10 g of 2-amino-5-phenyl-1,3,4-thiadiazole, 100 ml of ethanol and 9.6 g of acetylenedicarboxylic acid diethyl ester is heated on a water bath until a clear solution is formed. On standing overnight, the 2-phenyl-7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester crystallizes which is suctioned off and washed with a little ethanol. Mp: 169-172 ° C.

C Η N S

Calculated: 55.80% 3.68% 13.95% 10.64%

Found: 55.65% 3.80% 14.00% 10.87%.

Example 12 11.5 g of 2-amino-5- (p-methoxyphenyl) -1,3,4-thiadiazole are reacted in 100 ml of ethanol by analogy with the procedure described in Example 11 with 9.5 g of acetylenedicarboxylic acid diethyl ester. 7 g of crude thus obtained, melting at 216-218 ° C 2- (p-methoxyphenyl) -7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid Ethyl ester is added to a solution of 1.3 g of potassium hydroxide in 200 ml of ethanol. The reaction mixture is briefly heated to boiling and then left to stand overnight. Upon addition of water, the precipitated crystals are dissolved. Then, with hydrochloric acid, acidify to ca. pH 2. The crystals are aspirated, washed with water and dried. Thus, the 2- (p-methoxyphenyl) -7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid melting at 227-230 ° C is obtained during decomposition. .

10 142175

C H N S

Calculated: 51.53% 2.99% 13.87% 10.58%

Found: 51.16% 3.04% 13.61% 10.57%.

Example 13

Proceed as in Example 12 but use 13.2 g of 2-amino-5- (3 ', 4,4-dimethoxyphenyl) -1,3,4-thiadiazole instead of 2-amino-5- (p-methoxyphenyl) ) -1,3,4-thiadiazole and finally obtains 2- (31,4'-dimethoxyphenyl). -7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid. Mp: 150 C during decomposition.

C Η N S

Calculated: 50.40% 3.33% 12.62% 9.62%

Found: 49.95% 3.40% 12.74% 9.43%.

Example 14

By reaction of 9.7 g of 2-amino-5- (3,4,4,5-trimethoxyphenyl) -1,3,4-thiadiazole with 6.2 g of acetylene carboxylic acid diethyl ester in 200 ml of ethanol on Example 12, it is obtained as crude product at 205-207 ° C decomposing melting 2- (3 *, 4 ', 5'-trimethoxyphenyl) -7H-1,3,4-thiadiazolo- [3,2-a] -pyrimidine-7-On-5-carboxylic acid ethyl ester, which as described in Example 12 is transferred accordingly, at 220-223 ° C with decomposing melting free acid.

C Η N S

Calculated: 49.57% 3.61% 11.57% 8.83%

Found: 49.36% 4.00% 11.21% 9.09%.

Example 15

A mixture of 4.5 g of 2-amino-5- (thienyl-2 ') - 1,3,4-thiadiazole, 100 ml of 95% ethanol and 4.2 g of acetylenedicarboxylic acid diethyl ester is left to stand overnight. heat for 30 minutes to bring to a boil and allow to cool. The product is suction filtered, recrystallized from ethanol and finally washed with ether and dried. The 2- (thienyl-2 *) - 7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester is obtained in the form of the monohydrate. Mp: 184-186 ° C during decomposition.

li 1421 7 D

C H N S

Calculated: 44.30% 3.39% 12.92% 19.72%

Found: 43.87% 3.71% 12.87% 19.13%.

Example 16

A mixture of 6.5 g of 2-amino-5- (pyridyl-4 ') - 1,3,4-thiadiazole, 100 ml of glacial acetic acid and 6.3 g of acetylenedicarboxylic acid diethyl ester is heated briefly to 60 ° C and then allowed allowed to stand 1 day. Evaporate to dryness, tear the residue with a little acetic acid ethyl ester, extract and recrystallize from a little ethanol. There is thus obtained the melting 2- (pyridyl-4 ') -7H-1,3,4-thiadiazolo [3,2-a] pyrimide in 7-one-5-carboxylic acid melting at 185-187 ° C. -ethyl ter.

C Η N S

Calculated: 51.65% 3.31% 18.53% 10.60%

Found: 51.74% 3.27% 18.20% 10.64%.

Example 17 8.9 g of 2-amino-5- (pyridyl-3 ') - 1,3,4-thiadiazole, 50 ml of glacial acetic acid and 8.5 g of acetylenedicarboxylic acid diethyl ester are heated in a boiling water bath until a clear solution is formed. that is filtered over coal.

It is left to stand overnight, heated for 10-15 minutes by boiling and then evaporated to dryness. The residue is treated with acetic acid ethyl ester to make it crystalline. The 2- (pyridyl-3 ') - 7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ester thus obtained melts at 185-187 ° C with decomposition after recrystallization from a mixture of acetic acid ethyl ester and ethanol (2: 1).

C Η N S

Calculated: 51.65% 3.31% 18.53% 10.60%

Found: 51.79% 3.64% 18.38% 10.83%.

Example 18 2 g of 2-amino-5-benzyl-1,3,4-thiadiazole are added to 50 ml of ethanol and 1.6 g of acetylene dicarboxylic diethyl ester are added. After standing overnight, evaporate to dryness, add 50 ml of chlorobenzene and heat for 1 hour on boiling. After evaporation, the residue is dissolved in acetic acid ethyl ester which is filtered and by the addition of ether and petroleum ether precipitates 2-benzyl-7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one -5-carboxylic acid ethyl ester. Mp: 116-118 ° C.

Claims (1)

12 14217B C H N S Calculated: 57.11% 4.16% 13.32% 10.15% Found: 56.99% 4.13% 13.08% 9.98%. Example 19 8.1 g of 2-amino-5- (β-phenylethyl) -1,3,4-thiadiazole are heated in 100 ml of ethanol with 6.8 g of acetylenedicarboxylic acid diethyl ester until a clear solution is formed. After standing overnight, evaporate to dryness. Upon grating with ether, the residue becomes crystalline. There is thus obtained the 2- (β-phenylethyl) -7H-1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid ethyl ester, mp 95-98 ° C. C Η N S Calculated: 58.33% 4.59% 12.75% 9.73% Found: 57.76% 4.58% 12.61% 9.67%. Claims. Analogous process for the preparation of thiazolo or 1,3,4-thiadiazolo [3,2-a] pyrimidin-7-one-5-carboxylic acid derivatives. with the general formula X COOR X_N // vi R1 / 2 - 2 wherein X represents a nitrogen atom or the group R -C-, R is hydrogen, a pharmaceutically useful cation or an alkyl group having 1 'to 5' 2 carbon atoms, R and R is the same or different and - with the proviso that R cannot be hydrogen at the same time that R is hydrogen or methyl and that X cannot be nitrogen at the same time as R 1 is methyl - represents hydrogen, alkyl groups having 1 to 5 carbon atoms or phenyl, benzyl, phenylethyl, thienyl or pyridyl groups optionally substituted with 1 to 3 halogen atoms, alkyl or alkoxy groups having up to 4 carbon atoms in the alkyl group, or cycloalkyl groups having 5 to 7 carbon atoms, or pharmaceuticals usable salts of these compounds, characterized by condensing a compound of formula II