GB882531A - Chromium-containing monoazo dyestuffs - Google Patents

Abstract

The invention comprises chromium-complex monoazo dyestuffs of formula <FORM:0882531/IV (c)/1> wherein Ac is an acyl radical, R is a sulphonamide or alkylsulphone group which may be substituted, R1 is a radical of the benzene series which may be substituted other than by sulphonic or carboxylic acid groups and Me is an alkali metal ion. They are prepared by forming a 1 : 1-chromium complex of a dyestuff of formula <FORM:0882531/IV (c)/2> wherein X is hydroxy or a group convertible thereto during metallisation and reacting it with a monoazo dyestuff of formula <FORM:0882531/IV (c)/3> They are also obtained, in admixture with the symmetrical complexes, by treating a mixture of the dyestuff specified above with a chromiumyielding agent. They dye wool, silk, leather, polyamides and polyurethanes in yellow to green shades. In Examples: (1) the monoazo dyestuff 4 - nitro - 2 - aminophenol - 1 - methysulphonylamino-7-naphthol is heated in ethylene glycol with chromic chloride and the 1 : 1-complex obtained is reacted with the monoazo dyestuff 2 - amino - 4 - sulphonamido - phenol acetoacetanilide; (2) a mixture of the dyestuffs specified in (1) is heated in aqueous sodium hydroxide with potassium dichromate and glucose to give a mixture of chromium complexes. Many alternative reactants and dyestuffs are specified in examples. Specifications 272,908, 637,404, 667,168, 755,853 and 758,016 are referred to. Reference has been directed by the Comptroller to Specification 796,350.