Synthesis of thiazole derivatives
AssigneeAlbemarle Corporation
InventorsArcelio J. Malcolm, Tse-Chong Wu
Life of this patent
Estimating the term…
Abstract
N-4-(cyanoethylthiomethyl)-2-thiazolyl!guanidine--a key intermediate for preparing the pharmaceutical, famotidine--is produced by mixing in a liquid medium formed from a chemically indifferent organic solvent and water, and under an inert atmosphere, (i) a 2-guanidino-4-halomethylthiazole or a hydrohalide complex thereof, (ii) an S-(2-cyanoethyl)isothiourea or a hydrohalide complex thereof, and (iii) a strong alkali metal base. In lieu of (ii), an alkali metal salt of 2-cyanoethyl-1-thiol can be used, and in such case use of (iii) is optional, but preferable.
Claims10
A process comprising mixing in a liquid medium formed from at least one chemically indifferent organic solvent and water, and under an inert atmosphere:
- a) a 2-guanidino-4-halomethylthiazole or a 2-guanidino-4-halomethylthiazole hydrohalide or a combination thereof;
- b) an alkali metal salt of 2-cyanoethyl-1-thiol;
- and
- c) at least when a) is a 2-guanidino-4-halomethylthiazole hydrohalide or is said combination which includes a 2-guanidino-4-halomethylthiazole hydrohalide, a strong alkali metal base;
- in proportions and under reaction conditions such that N-4-(cyanoethylthiomethyl)-2-thiazolyl!guanidine is produced.
A process which comprises forming in a liquid medium formed from at least one chemically indifferent organic solvent and water, and under an inert atmosphere, a mixture of:
- a) a 2-guanidino-4-halomethylthiazole or a 2-guanidino-4-halomethylthiazole hydrohalide or a combination thereof;
- b) an alkali metal salt of 2-cyanoethyl-1-thiol;
- and
- c) at least when a) is a 2-guanidino-4-halomethylthiazole hydrohalide or is said combination which includes a 2-guanidino-4-halomethylthiazole hydrohalide, a strong alkali metal base;
- in proportions and under reaction conditions such that N-4-(cyanoethylthiomethyl)-2-thiazolyl!guanidine is produced.
Dependencies are inferred from the claim text.