WATER-INSOLUBLE AZO COLORANT CONSISTING ESSENTIALLY OF N-ACETOACETYLDEHYDROTHIOTOLUIDINE

PROBLEM TO BE SOLVED: To obtain a water-insoluble azo colorant consisting essentially of N-acetoacetyldehydrothiotoluidine having yellow color, a high heat stability and a high coloring power and useful as an azo pigment, etc., by coupling an diazotized product of a specific amino benzoic acid derivative with N- acetoacetyldehydrothiotoluidine. SOLUTION: This water-insoluble azo colorant consisting essentially of N- acetoacetyldehydrothiotoluidine is a new azo compound of the formula I [R1 and R2 are each H, a 1-4C alkyl, a 5-6C cycloalkyl, benzyl, an unsubstituted phenyl, etc.; R3 is H, a 1-4C alkyl, a 1-4C alkoxy, a halogen, nitro, cyano, hydroxyl, CF3 , the group of COO (1-4C alkyl), etc.; (n) is 1 or 2] and used for an organic substance having a high molecular weight, a paint, a coating material, a printing ink, a toner, a developing solution, etc., as an azo pigment, etc., having a yellow color, a high heat stability and a high coloring power. The compound is obtained by diazotizing an aminobenzoic acid derivative of formula II and thereafter coupling the diazotized compound with N- acetoacetyldehydrothiotoluidine in the mol ratio of 1:0.95 to 1:1.05.