GB1398015A - Water-insoluble monoazo dyestuffs and process for heir preparation - Google Patents

Abstract

1398015 Water-insoluble monoazo dyes HOECHST AG 16 June 1972 [18 June 1971] 28311/72 Heading C4P Novel water-insoluble monoazo dyes of formula where R is H or C 1 -C 4 alkyl; and X is H, halogen, methyl or methoxy are prepared by diazotizing an appropriate 5-amino-isophthalic acid monomethyl ester amide and coupling it with an appropriate 5-acetoacetylamino-benzimidazolone. Coupling may be effected in the presence of a surface active agent and possibly in the presence of a carrier such as heavy spar and may be carried out in water and/or an organic solvent such as glacial acetic acid, alcohol, dioxan, THF, formamide, DMF, DMSO or pyridine. The coupling mixture may advantageously be heated for a period of time, e.g. boiled or held under pressure at above 100‹C. optionally with the addition of a solvent -such as ethanol, ortho-dichlorobenzene or DMF or a resin soap and the product dyestuffs may be after treated with a solvent such as those referred to or chloro- or nitro-benzene or may be ground with auxiliaries. The pigments are suitable for the preparation of printing pastes, colour lakes and disperse coating colours-and for dyeing caoutchouc, plastic materials and natural or synthetic resins and for printing paper and textile materials. They may also be used for dyeing rayon from cellulose ethers or esters, polyamides, polyurethanes, polyglycol terephthalates or polyacrylonitrile. Yellow shades are obtained.