Para selectivity in catalyzed disubstitutions of monosubstituted benzenes containing meta-directing substituents

摘要

Para selectivity in the conversion of a monosubstituted benzene containing a meta-directing group to disubstituted benzenes can be substantially enhanced by carrying out the reaction in the gas phase with an inorganic or organic substitution agent in the presence of a catalyst composition comprising a crystalline molecular sieve material. In particular, nitrobenzene can be converted using nitrogen dioxide in the gas phase to a product containing an augmented proportion of para- dinitrobenzene using a wide range of catalyst compositions comprising both synthetic and naturally occurring crystalline molecular sieve materials such as ferrierites, X-type zeolites, Y-type zeolites, silicalite, framework-modified silicalites, ZSM aluminosilicates, AMS-1B borosilicates, and AlPO.sub.4 types.