GB896232A - New monoazo dyestuffs of the benzothiazole-azo-benzene series - Google Patents

Abstract

2 - Amino - 4 - chloro - 6 - nitrobenzothiazole is obtained by refluxing a solution of 2-amino-4-chlorobenzthiazol in pyridine and acetic anhydride to give 2-acetylamino-4-chloro-benzothiazole which is nitrated with nitric acid in sulphuric acid solution to give 2-acetylamino-4-chloro-6-nitrobenzothiazole which is finally hydrolysed with a mixture of ethylene glycol monoethyl ether and hydrochloric acid. N - g - Propionyloxypropyl - N - b - carbomethoxyethyl-m-toluidine is prepared by refluxing N - b - carbomethoxyethyl - m - toluidine with trimethylene chlorohydrin and acylating the N - b - carbomethoxy - N - g - hydroxypropyl - m - toluidine obtained with propionyl chloride.ALSO:The invention comprises water-insoluble monoazo dyestuffs of formula <FORM:0896232/IV (c)/1> wherein B is a hydrogen or halogen atom, X and Y are an -A.O.COR or -A.COOR radical and may be the same or different, wherein A is an alkylene radical and R is a substituted or unsubstituted alkyl or aryl radical, and Z is a hydrogen or halogen atom or an alkyl, alkoxy, trifluoromethyl or acylamino group, They are prepared (a) by coupling a diazotised 2-amino-benzthiazole with a N : N-disubstituted-aniline both components being appropriately substituted or (b) by treating a monoazo compound of formula <FORM:0896232/IV (c)/2> with an acid chloride or anhydride of an acid of formula R.COOH, wherein A, B, R and Z are as defined above and P is an -A.OH, -A.OCOR or A.COOR radical. The dyestuffs give red and violet shades on cellulose acetate and polyester fibres. In Examples (1) a solution of nitrosylsulphuric is added to a cooled suspension of 2-amino-4-nitrobenzthiazole in sulphuric acid and the diazo solution obtained is added to a solution of N : N-bis-(b -carbethoxyethyl)-m-toluidine in aqueous acetone and hydrochloric acid; other components specified in similar examples are N : N-bis-(b -acetoxyethyl)-n-acetylamino - aniline, N : N - bis - (b : carbo - ethoxy - ethyl or - methyl) - aniline, N : N - bis (b - carbomethoxy - methyl or - ethyl) - aniline, N : N - bis - (b - acetoxy - or - iso - butyryloxy - or - benzoyloxy - or - 4 - methyl - benzoyloxy - ethyl) - m - toluidine, N : N - bis - (b - acetoxyethyl) - m - chloro - or - trifluoro - methyl - aniline; 2 - amino - 6 - nitro - benz - thiazole and 2 - amino - 4 - chloro - 6 - nitro - benzthiazole; (2) the dyestuff 2-amino-6-nitro-benzthiazole --> N : N - bis - (b - hydroxyethyl) - aniline is refluxed in pyridine with acetic anhydride to give the acetyl derivative. Specifications 440,113, 551,434 and 787,369 are referred to.