NOVEL PROCESS FOR THE PREPARATION OF 4-METHYL-5-(2-CHLOROETHYL)-THIAZOLE AND ANALOGUES THEREOF.

摘要

The invention relates to 5-(2-chloro-C2-5-alkyl)-4-methyl-1,3-thiazoles of the general formula I, wherein R is a straight-chain 2-chloro-C2-5-alkyl group and a process for their preparation, which is characterized by (A1) reacting a 3-(2-chloro-C2-5-alkyl)-3-thiocyanato-2-propanone of the general formula IV in an organic solvent with gaseous hydrogen chloride to obtain the corresponding 2-chloro-5-(2-chloro-C2-5-alkyl)-4-methyl-1,3-thiazole of the general formula II or (A2) reacting a 3-(2-chloro-C2-5-alkyl)-3-thiocyanato-2-propanone of the above formula IV with an aqueous mineral acid to obtain the corresponding 5-(2-chloro-C2-5-alkyl)-2-hydroxy-4-methyl-1,3-thiazole of the general formula III and reacting the thus obtained compound of the formula III with a halogenating agent to obtain the corresponding 2-chloro-5-(2-chloro-C2-5-alkyl)-4-methyl-1,3-thiazole of the above formula II, and (B) hydrogenating the compound of the general formula II to obtain the 5-(2-chloro-C2-5-alkyl)-4-methyl-1,3-thiazole of the above general formula I. The invention further relates to intermediates for the above process, and pharmaceutical compositions comprising the compounds of formula I.