GB822948A - New azo pyrimidine dyestuffs - Google Patents

Abstract

The invention comprises dyes, free from SO3H or COOH groups, and of formula A-N(Z)-R, where R is H or a saturated hydrocarbon residue which may be substituted, A is an organic radicle containing at least one azo group attached to an aryl nucleus, N is attached to a carbon atom in A, and Z is a pyrimidyl nucleus, containing either two Cl atoms in two of the 2, 4 or 6 positions or a Cl atom in one of the 2, 4 or 6 positions and an electronegative group in the 5 position, which pyrimidyl nucleus may be substituted by an alkyl or aryl group. Specified values for R are methyl, ethyl, cyclohexyl and 2-hydroxyethyl. Specified electronegative groups are nitro, cyano and methyl- and ethyl-sulphonyl groups. Specified alkyl and aryl groups are methyl, ethyl and phenyl groups. The dyestuffs are made by normal diazotization and coupling methods or by treating a compound of formula A-NH-R with an appropriate tri- or di-chlor-pyrimidine, specified being 2,4,6-trichloro-and 5 - nitro - 2,4 - dichloro - 6 - methyl-pyrimidines. The reaction is preferably effected in a water-miscible medium in the presence of acid-binding agents. The above aminoazo compounds may be made in conventional fashion from diazo compounds of appropriate arylamines and amino coupling components or from appropriate acylamino-or-nitro-azo compounds. Specified arylamines include aniline, chloro-, methoxy-, methyl-, nitro-, phenyl-, phenoxy-, sulphonamido-, N-substituted sulphonamido-, acetylamino-, cyano-, trifluoromethyl- and ethylsulphonyl-anilines, acetyl-benzidine, a - and b -naphthylamines, 5-nitro-2-aminothiazole and 6 - methylsulphonyl - 2 - aminobenzthiazole. Indicated coupling components include aniline, methyl-, methoxy- and N-alkyl- and N-b 1-aminoethyl and - b - hydroxyethyl - anilines, 4 - acetylaminophenol, 1 - amino - 7 - naphthol, N,N - di - (b - hydroxyethyl) - m - phenylene diamine, 1 - (31 - and 41 - aminophenyl) - 3 - methyl - and - carbethoxy - 5 - pyrazolones. The aminoazo compounds may be dis - or polyazo compounds obtainable by the use of such arylamines as 4 - aminoazobenzene, 1 - (41-amino - 21 - methylphenylazo) - 2 - naphthol, 4-amino - 3 - methoxy - 6 - methyl - 41 - nitro-azoberzene. Preferred are dyestuffs where A is of formula C-N = N-B-, where C is a benzene ring carrying an electronegative group o- or pto the azo group or a benzthiazol- or thiazol-2-yl group and B is a benzene ring and B or C may carry additional substituents, and those where A is E-N = N-B-, where E is a benzene ring containing an OH group o to the azo group and B is as before and B or E may carry additional substituents. The dyestuffs may be admixed with surface active agents, e.g. with the condensation product of naphthalene-2-sulphonic acid and formaldehyde, and mineral oil added to give a non-dusting composition. The dyestuffs dye textiles made from artificial fibres, especially cellulose acetate and polyamides, from an aqueous dispersion in yellow, red and blue tints. Examples are provided of the preparation of the dyestuffs and their use in dyeing processes.