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.sup.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 .alpha.-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.degree. to about 110.degree. C., hydroxylamine, preferably the salts thereof such as [NH.sub.3 OH]Cl, [NH.sub.3 OH]HSO.sub.4, [NH.sub.3 OH].sub.2 SO.sub.4, and [NH.sub.3 OH]NO.sub.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.
本发明涉及一种新型的
2-氨基-5-氰基噻唑及其制备方法,该方法采用一种新的两步法。所述
氰基
噻唑的
化学式为##STR1##其中R.sup.1选自氢;1-20个碳原子的直链或支链烷基,其可以被1-3个卤素取代;苯基和1-3个卤素取代的苯基,1-20个碳原子的直链或支链烷基,1-20个碳原子的直链或支链烷氧基,
氰基,硝基或三
氟甲基;2-
噻吩;和α-
吡啶。这些化合物可用作通过重氮化和与类
苯胺偶联剂等化合物偶联制备的偶氮
染料中的重氮基。其制造方法包括在基本无
水的
甲酸中,在大约50°C到大约110°C的温度下反应
羟胺,优选其盐如[NH.sub.3 OH]Cl,[NH.sub.3 OH]HSO.sub.4,[NH.sub.3 OH].sub.2SO.sub.4和[NH.sub.3 OH]NO.sub.3,以及相应的2-
氨基-5-甲酰基
噻唑或其盐,其摩尔比为从大约1:1到大约2:1的反应物摩尔比,并且将中间体5-
氰基-2-甲酰胺基
噻唑水解为胺,可以在先前隔离或不隔离的情况下进行。