GB1528590A - Production of pure cationic dyes - Google Patents

Abstract

1528590 Azamethin dyes BASF AG 30 Dec 1975 53099/75 Heading C4P Cationic dyes of formula (in which each A is independently alkyl or are together alkylene; A<SP>1</SP> is optionally substituted alkyl; A<SP>2</SP> is H or completes an optionally substituted 5- or 6-membered ring fused to the ortho position of ring E and which optionally is substituted or has fused thereon a six-membered heterocycle; AS is an anion; rings B and E are optionally further substituted), are prepared by condensing at 0-50‹ C. in the presence of an inert organic solvent and aliphatic or aromatic carboxylic or sulphonic acid, an aldehyde of Formula II and an amine of Formula III The dyes may be precipitated from the reaction solution, if necessary by addition of acid. The examples relate to the preparation of dyes in which A is methyl; A<SP>1</SP> is methyl, ethyl or benzyl; A<SP>2</SP> is H and E is substituted by methyl, chloro or 1 or 2 methoxy groups, or A<SP>2</SP> and E together form a hexahydrocarbazole, 2-methyl-dihydroindole, dihydroindole, tetrahydroquinoline, 6-methoxytetrahydroquinoline or 4-methyl-tetrahydroquinoxaline nucleus; ring B is unsubstituted or substituted by chloro, methyl or methoxy; A<SP>#</SP> is hydrosulphate, hydrophosphate, chloride, citrate, tartrate, p-toluenesulphonate, formate, benzoate or acetate.