METHOD OF REPROCESSING NON-REACTED PRODUCTS IN THE PROCESS OF VITAMIN B SYNTHESIS Russian patent published in 1994 - IPC

FIELD: organic chemistry, vitamins. SUBSTANCE: method involves use if spirituous mother liquor, which is obtained by interaction of dihydro-or 2-methyl-4-amino-5-bromomethylpyrimidine monohydrobromide with 4-methyl-5-B₁-hydroxyethylthiazole. Then reaction mass is treated by boiling in ethanol, filtered, and spirituous mother liquor is obtained. The latter has hydrobromide salts of 4-methyl-5-β-hydroxyethylthiazole and 2-methyl-4-amino-5-ethoxymethylpyrimidine, and 4-methyl-5-b-hydroxyethylthiazole-base. Concentrate obtained from spirituous mother liquor is dissolved in the mixture toluene-and/or iso-butanol taken at volume ratio from 9: 1 to 7: 3 (3-5 volumes of mixture per 1 volume of concentrate). Concentrate is treated with 2-methyl-4-amino-5-ethoxymethylpyrimidine taken with equimole quantity with respect to hydrogen bromide. Formed 2-methyl-4-amino-5-ethoxymethylpyrimidine hydrobromide is separated and brominated. Method is used in synthesis of vitamin b. EFFECT: improved method of reprocessing. 3 tbl