PROCESS FOR PRODUCING DIAMINO-DIPHENYLMETHANE

1351632 Bis-(4-aminophenyl)-methane MAGYAR TUDOMANYOS AKADEMIA 19 April 1971 [2 March 1970] 22837/71 Heading C2C Bis-(4-aminophenyl)-methane is prepared by pre-mixing a mixture of aniline and a mineral acid with an aqueous solution of formaldehyde or a precursor thereof in a pre-mixing chamber and reacting the resulting mixture in a single stage in a tubular reactor in continuous operation to inhibit mixing of reacted with unreacted materials, the pre-mixing and subsequent reaction being performed at from 60 to 90‹ C. The mineral acid is preferably hydrochloric acid and the ratio of aniline to mineral acid is preferably not greater than 1À8 : 1. The product may be treated with an aqueous solution of an alkali metal hydroxide.