GB895240A - Basic dyestuffs - Google Patents

Abstract

Basic methine dyestuffs suitable for dyeing fibres of polyacrylonitrile or asymmetrical dicyanethylene have the general formula <FORM:0895240/IV (c)/1> wherein the benzene ring A may be substituted or bear a further fused-on benzene ring, R1 and R2 are C1-C5 alkyl groups, R4 is hydrogen C1-C5 alkyl, cyclohexyl, benzyl, substituted or unsubstituted phenyl or carboxylic acid, amide or C1-C5 alkyl ester, R6 is a C1-C5\t alkyl, cycloalkyl, aralkyl or aryl group, R7 is a C1-C5\t alkyl or benzyl group, R8 is substituted or unsubstituted C1-C5 alkyl, cycloalkyl, aralkyl, aryl or substituted aryl group and X1 is an anion. The dyes may be prepared by reacting a dye of the formula <FORM:0895240/IV (c)/2> wherein R3 and R5 may be hydrogen, substituted aryl, or the groups specified for R6, with an alkylating agent R7X1 such as dimethyl sulphate, diethyl sulphate, methyl iodide or methyl p-toluene sulphonate. Alternatively, a 2-methylene-indoline-o -aldehyde may be reacted with a 1,2,3-substituted-5-pyrazolone in an acid medium such as phosphorus oxychloride, or a 2-methylene-indoline may be reacted with a 1,2,3-substituted-5-pyrazolone-4-aldehyde in an acid medium such as phosphorus oxychloride or acetic acid. The benzene ring of the indoline nucleus may contain chloro, bromo, nitro, methyl, methoxy, ethoxy, amino, acetamino, cyano, carbamido, carbomethoxy, carbethoxy, methylsulphonyl, sulphamido or methyl-, ethyl-or phenyl-sulphonylamino substituents. The group R8 may be b -cyanoethyl, phenyl or phenyl substituted with methyl, chloro, nitro, amino or carboxyl groups.