application background | thiazole ring is a kind of important five-membered aromatic heterocycle containing nitrogen-sulfur heteroatoms. its special structure makes thiazole compounds have broad application prospects in many fields such as chemistry, pharmacy, biology and materials science, showing great development value, it has received widespread attention. In the field of medicine, thiazole compounds can combine with a variety of enzymes and receptors in organisms to show a variety of biological activities, almost covering the entire field of medicine, and there are many thiazole compounds used in clinical. |
Preparation | Using 4-oxopiperidin-1-carboxylic acid tert-butyl ester as the starting material, the key intermediate 3-bromo-4-oxopiperidin-1-carboxylic acid tert-butyl ester is prepared by bromination reaction, the target compound 2-bromo-6, 7-dihydrothiazole [5,4-C] pyridine-5 (4H)-carboxylic acid tert-butyl ester was prepared by cycliding with thiourea. The synthesis reaction formula is as follows: 2-bromo-6, 7-dihydrothiazole [5,4-C] pyridine-5 (4H)-carboxylic acid tert-butyl ester synthesis reaction formula The novel compound of the present invention was prepared according to the following experimental procedure using appropriate materials and appropriate conditions. Preparation of 3-bromo-4-oxopiperidine-1-carboxylic acid tert-butyl ester Take a clean single-port reaction flask, add a mixed solution of tetrahydrofuran and ether, and dissolve 4-oxopiperidine-1-carboxylic acid tert-butyl ester and aluminum chloride in a mixed solution of tetrahydrofuran and ether. After the system is cooled to 0°C, add liquid bromine and stir at low temperature for 30 minutes. The reaction materials were stirred at 0-5°C for 24 hours. After the reaction is completed, the obtained solid is filtered and then the mother liquor is concentrated under vacuum. The crude substance obtained was ground with ether, the solids were filtered and dried under vacuum to obtain the title compound, 3-bromo-4-oxopiperidine-1-carboxylic acid tert-butyl ester. Preparation of 2-bromo-6, 7-dihydrothiazole [5,4-C] pyridine -5(4H)-carboxylic acid tert-butyl ester Take a clean single-port reaction flask, add isopropanol solution, and refluxing 3-bromo-4-oxopiperidine-1-carboxylic acid tert-butyl ester and thiourea in isopropanol solution for 1 hour. After the reaction was completed, the reaction material was concentrated and the resulting crude substance was ground with diethyl ether, the solids were filtered and dried under vacuum to obtain the title compound 2-bromo-6, 7-dihydrothiazole [5,4-C] pyridine-5 (4H)-tert-butyl carboxylate. |