Azo dyes, process for their preparation and use thereof

摘要

Disazo dyes of formula (I) are new; in which R1, R2 = 1-4 C alkyl or 1-4 C alkoxy, opt. substd. by OH, 1-4 C alkoxy or halogen; phenyl or phenoxy, opt. substd. by 1-4 C alkyl, 1-4 C alkoxy or halogen; or -N(R3)R4; R3, R4 = H; 1-4 C alkyl; or 2-4 C alkanoyl, opt. substd. by OH or 1-4 C alkoxy; with the proviso that not both R1 and R2 = Me. Also claimed is the prepn. of (I) by diazotising an aminoazobenzenesulphonic acid of formula (II), coupling with a coupling component of formula (III) and reacting the prod. with a gp. introducing the -C(O)-R1 gp..