SU1694584A1 - Method of 3-benzoyl-7-oxothiazolo-[3 - Google Patents

Abstract

The invention relates to heterocyclic substances, in particular the preparation of 3-benzoyl-7-oxothiazolo 3,2-a pyrimidine-8-line, 6-ida, an intermediate for the synthesis of active substances. The goal is to create a proposed method for obtaining a new compound of this class. Synthesis is carried out by reacting thiouracil with 1-bromo-2-benzoyl acetylene in an equimolar ratio in dimethylformamide and methanol, taken in a volume ratio of 1: 3, at 60-65 ° C. Output 92%; t pl. 237-238 ° C, gross f-la Ci3H8N202S

Description

This invention relates to the chemistry of heterocyclic compounds, namely, to a new method for the preparation of a new meso-ionic condensed heterocyclic compound: 3-benzoyl-7-oxothiazole-3-irimidine-B-ih b-ida of formula jj

° - N.S

H

II

CH

$ © G

cyN-c-coc6H5

(one)

The aim of the invention is to create a new method of obtaining a new representative of the class of thiazolo, 3,2-a pyrimidine, meoionic 3-benzoyl-7-oxothiazolo, 3,2-a pyrimidine. which can be used in organic synthesis and in medicine

The interaction is as follows:

cl

00

B

VVS

+ HCS "S-SOSbN5 -

n

Thiazolo 3,2-a pyrimidines are intermediates for fine organic synthesis, as well as compounds with various types of pharmacological activity, which are used in medicine.

; ed c s-c-coc6Hs n

PRI me R 1. 3-Benzoyl-7-oxothiazo 3,2-a pyrimidine-8-i-6-id

A solution of 2.09 g (0.01 mol) of 1-bromo-2-benzoyl acetylene in 15 ml of methanol was added dropwise with vigorous stirring to a solution of 1.28 g (0.01 mol) of thiouracil in ml DMFA heated to 60 ° C. and continued to stir at 60 ° C. The total reaction time was 7 hours. The solution was cooled, the precipitated precipitate was filtered and washed on the filter with cold methanol. Yield 2.4 g (92%). Light brown crystals with mp. 237-238 ° C, the product is well soluble in DMF, DMSO, limited in alcohol, chloroform, acetone, insoluble in water.

Found,%: C 60.82; H 3.20; N 10.64; 3 11.97.

 Ci3H8N202S

Calculated,%: C 60.94; H 3.13; N 10.94; S 12.50.

IR spectrum, vcM OStC-S), 1525 (), 1625, 1655 (), 1665 (), 3040, 3080 (CH, NH).

NMR13S spectrum in DMF-o 7, d ppm;

126.1 (C-2), 133.4 (C-3), 137.2 (0-5), 111.6 (C-6), 182.6 (C-7), 163.5 (C-9 ), 184.5 (CO-Ph), 129.4137 .2 (CbH5).

Mass spectrum, t / e: 256 (M4), 228, 227, 179, 152, 105, 77.

The crystal and molecular structure of compound (I) was studied by X-ray structural analysis and the meso-ionic structure of compound (I) was confirmed with a positive charge on the N-8 atom and a negative charge on the C-6 atom.

PRI mme R 2. The reaction is carried out similarly to the conditions of Example 1 at 0 ° C. The yield of compound (I) is 15%.

PRI me R 3. The reaction was carried out similarly to the conditions of Example 1 at 22 ° C. The yield of compound (I) is 25%.

PRI me R 4. The reaction is carried out similarly to the conditions of example 1 at 50 ° C. The yield of compound (I) is 72%.

EXAMPLE 5 The reaction is carried out in the same manner as in Example 1 at 55 ° C. Compound (I) yield 85%,

Example 6: The reaction is carried out in the same manner as in Example 1 at 65 ° C. The yield of the compound (I) is 89%.

0

five

0

PRI me R 7. The reaction is carried out similarly to the conditions of example 1 at 90 ° C. The resinification of the reaction mixture is observed. The yield of compound (I) is 22%.

Example The reaction is carried out analogously to example 1 in DMF + MeOH (1: 3) in the presence of 1 g (0.01 mol) of triethylamine at 60 ° C for 4 hours. The yield of compound (1) is 45%.

EXAMPLE 9 The reaction is carried out analogously to Example 1 in DMF + MeOH (1: 3) in the presence of 0.56 g (0.01 mol) KOH at 20 ° C for 21 hours. Yield of compound (I) 60%.

As can be seen from the above examples 1-7, the maximum yield of the target product, 92%, is obtained by carrying out the reaction at 60 ° C. Lowering the temperature (50-55 ° C) with the same reaction time (7 hours) leads to a decrease in the yield of the target product to 72-85%, and at 0 ° C its output is only 15%.

A slight increase in temperature to 65 ° C leads to a decrease in the yield of the target product (89%), and at 30 ° C 5 its output sharply decreases to 22% due to the strong resinification of the reaction mixture, apparently at this temperature the initial 1-bromine 2-benzoyl acetyl. At 90 ° C, the desired product is obtained in higher yield (above 30%) while reducing the duration of the reaction is not possible,

The use of a base for binding the formed HBr in the process does not give a positive effect (examples 8 and 9).

Claims (1)

Invention Formula Method for preparing 3-benzoyl-7-oxo-aa, 2-a pyrimidin-8-linear-6-ida of formula 1H , Ph 0 five 0 H, WITH SOS6Nd H characterized in that thiouracil is reacted with 1-bromo-2-benzoylacetylene at an equimolar ratio of the reactants in dimethylformamide and methanol, taken in a volume ratio of 1: 3, respectively, at 60-65 ° C.