Patent ID: 6642388
Filing Date: 2003-11-04
Classification: C07D,C07K

Abstract:
A process for preparing 2-aminomethyl-4-cyanothiazole and its salts of the formulae 1a and 1b in whichn=1 or 2 and, for n=1, X is chloride, bromide, triflate or hydrogen sulfate and for n=2, X is sulfate, comprising a) reacting a thioamide of the formula IV with a bromopyruvate of the formula V, in which R1 is branched or linear C1-4-alkyl in an alcohol R2OH in which R2 is branched or linear C1-8-alkyl, HOâ€”CH2â€”CH2â€”, HOâ€”CH2â€”CH2â€”CH2â€” or C1-4-alkyl-Oâ€”CH2â€”CH2â€” at from âˆ’5Â° C. to 40Â° C. to produce a thiazole carboxylic ester of the formula VI, in which R1 is branched or linear C1-4 alkyl; b) reacting the thiazole carboxylic ester of formula VI in an alcohol R2PH at from 0Â° C. to 40Â° C. with from 5 to 50 molar equivalents NH3 of an aqueous ammonia solution where R2 is as described above to produce a thiazole carboxamide of the formula VII â€ƒc) dehydrating the amide VII to form BOC-protected 4-cyanothiazole of the formula VIII â€ƒand d) removing the BOC protective group.