GB317431A - Process for the manufacture of azo dyestuffs - Google Patents

Abstract

317,431. Carpmael, A., (I. G. Farbenindustrie Akt.-Ges.). May 16, 1928. Samples furnished Azo dyes are made by coupling a diazo compound of a sulphonic acid, carboxylic acid, bydroxycarboxylic acid or sulphocarboxylic acid of the benzene or naphthalene series with a middle, component, condensing with a nitrobenzoylchloride or a derivative thereof, reducing the nitro group to the amino group (so that the aminoaroyl residue can be introduced again if desired), diazotizing. and coupling with an aminophenylpyrazolone or a derivative thereof and, if desired, rediazotizing the disazo dyestuff in substance or on the fibre and combining with a coupling component. The following examples are specified. (1) The dyestuff 2-naphthylamine- 4 : 8-disulphonic acid # p-xylidine is condensed with p-nitrobenzoylchloride, the nitro group reduced, diazotized and coupled with m-amino-1- phenyl-3-methyl-5-pyrazolone. When developed on the fibre with #-naphthol or 1-phenyl-3- methyl-5-pyrazolone, orange and yellow shades respectively are obtained. (2) The dyestuff 2- naphthylamine-4: 8-disulphonic acid # oanisidine is condensed with p-nitrobenzoylchloride, the nitro group reduced and the product again condensed with p-nitrobenzoylchloride. The resulting nitro-compound is reduced, diazotized and coupled with m-amino-1-phenyl-3- methyl-5-pyrazolone. When developed with #- naphthol or 1 - phenyl - 3-methyl-5-pyrazolone, orange and yellow shades respectively are obtained. (3) The dyestuff obtained according to Example 2 is diazotized and coupled with #- naphthol. Other end components specified are aminonaphthols, alpha- and #-naphthol sulphonic acids or acyl- or aryl-aminonaphthol sulphonic acids, such as N-acetyl-H-acid, 1-naphthol-5-sulphonic acid and N-phenyl-2: 8: 6-acid.