GB1380677A - Disazo dyestuffs containing sulphuric ester groups - Google Patents

Abstract

1380677 Disazo dyestuffs containing sulphuric ester groups BAYER AG 19 April 1973 [20 April 1972] 18993/73 Heading C4P Novel disazo dyestuffs have the formula wherein A is C 2-4 alkylene, D is a radical of a diazo component of the benzene or naphthalene series which is free of SO 3 H and CO 2 H groups, B is an SO 3 H- and CO 2 H-free 1,4-phenylene or 1,4-naphthylene radical, and K is an SO 3 H- and CO 2 H-free coupling component radical. They contain only one -O-A-O-SO 3 H group and this is bonded to a carbon atom of an aromaticcarbocyclic or aromatic-heterocyclic ring in B or K. They are prepared by conventional coupling methods using components which either already contain the -O-A-O-SO 3 H radical or which contain the -O-A-OH radical; in the latter case this radical is subsequently sulphated either in the monoazo dyestuffs first formed from diazotized DNH 2 compounds and appropriate anilines or naphthylamines, or in the final disazo dyestuffs formed from said monoazo dyestuffs and appropriate coupling components. In the first coupling component the amino group may be protected by a group R (R=-SO 3 H or -CH 2 SO 3 H) in which case this group must be split off before the second coupling can be effected. Products containing a free phenolic OH group in K may subsequently be etherified by alkylation with, for example, a dialkyl sulphate, an alkyl halide, chloroacetonitrile, ethylene oxide or ethylenechlorohydrin. Intermediates of the formulae are isolated. The novel dyestuffs are used to dye nitrogencontaining fibre materials in yellow, orange, scarlet-red, bluish-tinged red and claret shades.