VERFAHREN ZUR HERSTELLUNG VON 2-NITRO-4-SULFAMYL-DIPHENYLAMIN-FARBSTOFFEN.

摘要

2-Nitro-4-sulphamyl diphenylamine dyestuffs (I) are produced by (1) sulphonating o-nitrochlorobenzene (II) with ClSO3H at ca. 100-110 deg.C to 4-chloro -3-nitrobenzenesulphonic acid (III); (2) reacting (III) with SOCl2 at ca. 70-80 deg.C to give highly pure 4-chloro -3-nitrobenzenesulphochloride (IV), (3) crystallising (IV) by adding the reaction mixt. to ice; (4) condensing (IV) with an aliphatic amine (VA) or aromatic amine (VB), suspended or dissolved in an aq. soln. of a basic condensing agent (VI) in the presence of a (non)ionic surfactant (VII) at ca. 5-50 deg.C and pH 7.5-12.5; and then (5) condensing with (VB), suspended or dissolved in an aq. soln. of (VI) at ca. 80-100 deg.C and the same pH. In the formula, R1 and R2 independently are H, Cl, Br, 1-4C alkyl, 1-4C alkoxy or phenoxy, opt. with a Cl, Br, 1-4C alkyl, 1-4C alkoxy or CF3 substit. in the benzene ring or naphthyloxy; R2 may also be -N(1-4C alkyl)2, -NH(1-4C alkyl), -NH(1-4C alkyloyl) or -NH-benzoyl; R3 and R4 independently are H, 1-4C alkyl, 1-2C alkoxy-1-4C alkyl or 5-6C cycloalkyl; R4 may also be phenyl, opt. substd. by Cl, Br, 1-4C alkyl, 1-4C alkoxy, -N(1-4C alkyl)2, -NH(1-4C alkyl), -NH(1-4C alkyloyl), -NH-benzoyl, phenoxy (opt. with a Cl, Br, 1-4C alkyl, 1-4C alkoxy or CF3 substit. in the benzene ring) or naphthyloxy.