SU362016A1 - METHOD FOR OBTAINING DERIVATIVES OF 2-AMINO OR 2-ACYLAMINOTHIENE - Google Patents

Description

one

The invention relates to the field of production of New thieno- (2,3-d) -thiazole derivatives, which can be used in the synthesis of biologically active substances, sensitizers, photographic emulsions and dyes for synthetic fibers.

In the literature, there is only information about the production of 2-methylthieno- (2,3-d) -thiazol by the oxidation of 2-thioacetyl-aminothiophene with potassium-sintered potassium in the presence of sodium hydroxide with a yield of about 1CX / D.

The purpose of the invention is to obtain new thienothiazole derivatives with good yields.

The proposed method for the preparation of 2-amino or 2-acylaminothieno- (2,3-y) -thiazole of the general formula

NHR.

where RI, R2 is hydrogen, alkyl, aryl, aralkyl, three-seven-membered heteryl, or Ri and Ra together form the group - (CH3) -, in which n 3,

Rs is —CO-alkyl, —CO-aryl, —CO-aralkyl, —CO — three-membered heteryl, hydrogen.

is that 2-acylamino-3-rhodanothiophene is heated, preferably in an organic solvent, for example ethyl benzoate.

Products are isolated by known res. M. To obtain 2-aminothieno- (2,3-d) -thiazole, the resulting 2-acylamino compound is subjected to acidic hydrolysis, for example, with hydrochloric acid in an aqueous dioxane solution.

The yield of products is 64-77%.

Example 1. 2-Acetylamino-5,6,7,8-tetrahydrothionaphthene- (2,3-d) -thiazole.

A mixture of 8.1 g of 2-apethylamino-3-rodan-4,5,6,7 tetrahydrothionaphthene and 7.5 ml of ethyl benzoate

boil for 10 min. The reaction mixture is cooled, the precipitate is filtered off, washed with methanol. The output of 2-acetylamino-5,6,7,8 tetrahydrothionaphthene- (2,3-d) -thiazole 6.8 g (84%), so pl. 259.5-261 ° С (from acetone).

Found, o / o C 52.45; H 4.84; N 11.23; S 25.70.

C, iH, 2N2OS2.

Calculated,%; C 52.35; H 4.79; N 11.10; S 25.41.

At capacity 2. 2.-Acetylamino-5,6-dimethylthieno- (2,3-d) -thiazole

For the test, 3.2 g (0.014 mol) of 2-acetylamino-3-rhodane-4,5-dimethylthiophene, 5 ml of ethyl benzoate are taken. Reaction and Excretion

carried out under the conditions of example 1. The yield of 2-acetylamino-5, b-dimethyl 10 - (2,3-d) - thiazole, 2.15 g (67.3%), so pl. 281.5-282.5 ° (from dioxane).

Found, with 48.07; H 4.35; N 12.09; S 27.90.

CgHioNsSsO.

Calculated%

C, 47.76; Ы 4.40; N 12.38; S 28.33.

Example 3. 2-Benzoylamino-5,6-dimethylthieno (2,3-d) -thiazole

1.8 g (0.0065 mol} of 2-benzoylamino-3-rodan-4, 5-dimethylthiophene, 2 ml of ethyl benzoate are taken for the experiment. The reaction and the release of the substance are carried out under the conditions of example 1. The yield is 2-benzoylamino-5 , 6-dimethylthieno - (2,3-d) - thiazole 1.2 g (66.4%), t. 1PL. 239.5-248 ° С (from a mixture of dioxane and methanol 3: 1).

Found, o / „: C 58,22; H 4.20; N 9.71; S 22.20.

CuHiaNsOSa.

Calculated,%:

C 58.30; H 4.19; N 9.71; S 22.24.

Example 4. 2-Amino-5,6,7,8-tetrahydrothionaphthene- (2,3-d) -thiazole.

iK boiling solution of 4.7 g (0.0185 mol) of 2-acetylamino-5,6,7,8 - tetratidrothionapheno (2,3-d) -thiazole in 70 ml of dioxane was added 50 ml of concentrated hydrochloric acid acid. The reaction mixture is boiled for 1.5 hours, cooled, the precipitate is filtered off, washed with water. The precipitate is suspended in 40 ml of water, 1.5 g of sodium bicarbonate is added and boiled for 10 minutes. The reaction mixture is cooled, the precipitate is filtered, The yield of 2-amipo-5,6,7,8-tetrahydrothionaphteno (2,3-d) -thiazole 3 g (77%), mp 169-170 ° (from methanol).

Found C, 51.13; H 4.68; N 13.34; S 30.24.

C9HioN2S2.

Calculated,%: C, 51.39; H 4.79; N 13.32; S 30,58.

Example 5. 2-Amino-5,6-dimethylthieno (2,3-d) -thiazole

For the experiment, 1.9 g (0.0084 mol) of 2-acetyl-yno-5, 6-dimethylthieno - (2,3-d) -thiazole, 60 ml of dioxane, 40 ml of concentrated hydrochloric acid, 25 ml of WATER, 0.8 sodium bicarbonate. The reaction and the isolation of the substance were carried out under the conditions of Example 4. The yield of 2-amino5, 6-dimethylthieno- (2,3-d) -thiazole 1 g (64.5%), m.p. 187-188 ° (from 75V () - Horo aqueous methanol).

Found,%; C 45.70; H 4.37; N 15.20; S 34.73.

CyHgNsSs.

Calculated,%: C 45.62; H 4.37; N 15.20; S 34.79.

Subject invention

Claims (2)

I. Method for preparing 2-amino or 2-acylaminothieno- (2,3-d) -thiazole derivatives of the general formula where RI, Ra is hydrogen, alkyl, aryl, aralkyl, three is a seven-membered heteryl, or Ri and Ra together form a group - (CH2) n-, in which, Ra is a group --CO-alkyl, -CO-aryl, -CO-aralkyl, -CO-three-semestershied heteryl, hydrogen, characterized in that 2-acylamino-3-rhodapothiophene is subjected to cyclization by heating, the products obtained are isolated or subjected to acidic hydrolysis by known methods. 2. A method according to claim 1, characterized in that the process is carried out in an organic solvent medium.