GB1432296A - Disazo dyestuffs - Google Patents

Abstract

1432296 Disazo dyestuffs BAYER AG 4 April 1974 [5 April 1973] 15005/74 Heading C4P Novel dyes of formula (where A is C 2 -C 5 alkylene; R 2 to R 4 are H, hal, optionally substituted alkyl or alkoxy; R 5 is optionally substituted C 1 -C 4 alkyl; B is a 1,4-phenylene or 1,4-naphthylene radical and D may contain up to four further substituents chosen from halogen or optionally substituted alkyl or alkoxy) are prepared by alkylating the corresponding dyes of the above formula where R 5 is H. The latter dyes are obtained by reacting the appropriate diazotized sulphato-alkoxy aniline with an amine of formula where Z is H, SO 3 H or -CH 2 SO 3 H; then after splitting off the Z group where necessary, the diazotized monoazo dyes are reacted with the appropriate phenol. Alternatively the starting dyes may be prepared using the corresponding hydroxy alkoxy-anilines and forming the sulphato alkyl group at an intermediate stage before the alkylation, by reacting with a sulphonating agent. The dyes are used for dyeing or printing, in yellow to red shades, nitrogen containing fibres particularly wool, silk, synthetic polyamide and polyurethane fibres.