2-Amino-5-cyanothiazoles and their preparation

Abstract

Abstract Disclosed are novel 2-amino-5-cyanothiazoles and the preparation thereof by a novel, two-step process. The cyanothiazoles have the formula ##STR1## wherein R 1 is selected from hydrogen; straight or branched alkyl of 1-20 carbons which may be substituted with 1-3 halogens; phenyl and phenyl substituted with 1-3 halogens, straight or branched alkyl of 1-20 carbons, straight or branched alkoxy of 1-20 carbons, cyano, nitro or trifluoromethyl; 2-thiophene; and α-pyridine. These compounds are useful, for example, as the diazo moiety of azo dyes prepared through diazotization and coupling with compounds such as aniline type couplers. The process for their manufacture comprises reacting in substantially anhydrous formic acid at from about 50° to about 110° C., hydroxylamine, preferably the salts thereof such as [NH 3 OH]Cl, [NH 3 OH]HSO 4 , [NH 3 OH] 2 SO 4 , and [NH 3 OH]NO 3 , and the corresponding 2-amino-5-formylthiazole or a salt thereof in a mole ratio of said reactants of, for example, from about 1:1 to about 2:1, and hydrolyzing the intermediate 5-cyano-2-formamidothiazole to the amine with or without prior isolation thereof.

Inventors

• 👤 Mark D. Frishberg

Bibliographic Details