PURPOSE: To readily produce a diphenylamine having a substituent group on the phenyl group, e.g. by reacting a phenol with ammonia in the presence of a hydrogen transfer catalyst and a cyclohexanone.
CONSTITUTION: A diphenylamine of formula III is produced by reacting a phenol of formula II with ammonia in the presence of a hydrogen transfer catalyst and a cyclohexanone of formula I [R is an alkyl, a cycloalkyl, an alkoxy, an aryl or an aryloxy; (n) is 1 to 5] or by converting a part of a phenol of formula II to a cyclohexanone of formula I in the presence of a hydrogen transfer catalyst under pressurized hydrogen and then reacting ammonia therewith using the remaining phenol of formula II as a hydrogen acceptor while forming the cyclohexanone of formula I in the reactional system. The reaction is carried out preferably by supplying ammonia in portions or continuously. The compound of formula III is useful as an anitoxidant for a mineral oil, a synthetic oil, etc., or a resin additive.
WADA MASARU
NAGATA TERUYUKI
