METHOD OF PREPARING LACTAM Russian patent published in 2000 - IPC

FIELD: preparation of aliphatic lactams used in production of polyamides. SUBSTANCE: lactam is prepared by hydrolysis with water in vapor phase at 200-450 C of aliphatic aminonitrile containing C₃-C₁₂ alkyl. Catalyst is aluminium oxide with specific surface of 10-280 sq.m/g and with volume of pores having pore diameter of more than 500 A from 10 to 45 ml/100 g. Water to aminonitrile molar ratio is (0.5- 50):1. EFFECT: high selectivity of process and long service life of catalyst and fewer regeneration cycles. 8 cl, 28 ex, 4 tbl