3-dimethyl-substituted indoline dyestuffs

The Specification relates to methine dyes of the general formula: wherein R1 is hydrogen, chlorine, bromine, alkyl, alkoxy, hydroxy alkoxy, amino, acetylamino, benzoylamino, nitro, sulphonamido, alkylsulphonamido, alkyl sulphonyl, alkylsulphonylamino, phenylsulphonylamino, phenyl or carbalkoxy, or represents a fused-on benzene ring, R3 is hydrogen or alkyl, R41 is a cyano, acyl or carbalkoxy group and R5 is the residue of a 5-pyrazolone, cyanacetic acid or an alkyl ester, substituted alkyl ester or amide thereof, or of malonic acid dinitrile, the residue R5 being free from sulphonic acid groups and all the said alkyl and alkoxy groups containing from 1 to 5 carbon atoms. The dyes are prepared by condensing a compound R5H2 with a 3;3-dimethyl-2-methylene -indoline-o -aldehyde having also an o -cyano, acyl or carbalkoxy substituent (R41), preferably in an alkaline medium. An emulsifying agent such as polyoxyethylene oleyl ether also may be present. In the case where R5 is the residue of a 5-pyrazolone, the dyes may be prepared by reacting a 3;3-dimethyl-2-methylene-indoline having an o -cyano, acyl or carbalkoxy substituent (R41) with a 5-pyrazolone having in its 4-position a -CHO or =CH-N(alkyl)2 group, preferably in an acidic medium. Dyes are specified wherein the substituent R1 in the indoline component is methyl, methoxy, carbomethoxy or chlorine. Pyrazolone components are specified having a 1-phenyl, chlorophenyl, dichlorophenyl, nitrophenyl, or methylphenyl substituent and a 3-methyl or carboxylic acid, ester or amide substituent. The group R41 may be cyano, benzoyl or carbethoxy. Specification 929,394 is referred to.