METHOD OF PREPARING CYCLIC LACTAMS Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: cyclic lactams are prepared by hydrolysis of aliphatic aminocarboxylic acid nitriles in liquid phase in reactor with fixed heterogeneous catalyst bed which contains no components soluble under process working conditions. The claimed method uses aminocarboxylic acid nitrile solution having concentration of 1-50 wt % in water or in admixture of water with organic solvent. Caprolactam is prepared from nitrile -6-aminocarboxylic acid. EFFECT: separation of catalyst from liquid reaction products is made easier, catalyst consumption is decreased and yield of final product is increased. 5 cl, 27 ex, 4 tbl