Allied Corporation

James E Galle

Frank Mares

Rose M Federici

Reginald T Tang

Steven E Diamond

Francis J Regina

Reginald Y Tang

Jeffrey Corsi

A process for selective preparation of lactams which comprises contacting, in the vapor phase, an aliphatic or aromatic aminonitrile having the formula HR.sub.1 N--D--CN wherein D is a divalent organic moiety and wherein R.sub.1 is (C.sub.1 -C.sub.4) alkyl or hydrogen with an effective amount of a silica catalyst, in the form of substantially spherical beads having a BET surface area greater than about 250 m.sup.2 /g, preferably between 300 and 500 m.sup.2 /g, and an average pore diameter less than about 20 nanometers preferably 8-10 nanometers at a temperature in the range of about 200.degree. to about 400.degree. C. and at a hydrogen or inert gas flow with a pressure in the range of about 0 to about 300 kPa, in the presence of: (a) ammonia in an amount equal to from 0 to about 50 mole percent of the molar amount of aliphatic or aromatic aminonitrile present; and (b) water in an amount from at least about 1.0 to about 50 times the molar amount of aliphatic or aromatic aminonitrile present for a time sufficient to produce the corresponding lactam is disclosed. The preferred aminonitrile is .epsilon.-aminocapronitrile. A process for the selective conversion of aliphatic or aromatic aminonitriles having the formula HR.sub.1 N--D--CN into the corresponding lactam in the presence of alkyl or aryl mononitrile or alkylene or arylene dinitriles by use of a silica catalyst, preferably a spherical silica catalyst with recovery of substantially all the alkyl or aryl mononitrile or alkylene or arylene dinitrile originally present is also disclosed.

Use of silica catalyst for selective production of lactams

Process for the selective conversion of dinitriles into the corresponding lactam by treating the dinitrile with an effective amount of a hydrogenation catalyst such as copper chromite in combination with a co-catalyst, such as titania, at a temperature in the range of from about 200.degree. C. to about 400.degree. C. and at a pressure of at least 50 kPa in the presence of water and hydrogen.

Selective conversion of aliphatic and aromatic aminonitriles and/or

A dinitrile is hydrogenated to an omega-aminonitrile with hydrogen with a supported highly dispersed rhodium catalyst and only ammonia present. The catalyst is prepared by hydrolyzing a rhodium(III) halide or nitrate with strong aqueous base at elevated temperatures, drying the supported rhodium hydroxide at elevated temperatures and intimately contacting with hydrogen the dried product with hydrogen at 260.degree.-360.degree. C. High conversions, selectivity to aminonitrile and long catalyst service times and catalyst recyclability are achieved in the absence of an aprotic solvent.

Selective hydrogenation of aliphatic dinitriles to omega-aminonitriles

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Madison, NJ, United States of America

James E Galle