Patent ID: 6545148
Filing Date: 2003-04-08
Classification: C07D

Abstract:
A process for preparing a caprolactam compound of formula I whereR1 is (C1-6)alkyl or (C3-6)cycloalkyl; R2 is hydrogen or (C1-6)alkyl; X is (C1-12) alkylene; (C2-12) alkenylene; or (C2-12) alkynylene; m is 0 or 1; and R3 is (C3-8)cycloalkyl; or an aromatic ring system selected from II, III, IV and V: â€ƒwhere R4 is hydrogen, chloro, or methoxy; R5 is hydrogen, chloro, (C1-18)alkyl or (C1-18)alkoxy; and Z is oxygen, sulfur, Nâ€”H, or Nâ€”CH3; or a pharmaceutically acceptable acid addition salt thereof, where possible, which process comprises, in a first step, acylating an aminocaprolactam compound of formula VI or an acid addition salt thereof, with a lactone compound of formula VII in the presence of: 1) a weak base; and 2) a polar organic solvent to obtain a diamide compound of formula VIII where each of R1, R2, X, m and R3 is as defined above and, in a second step, hydrolyzing the diamide compound obtained in the first step by dissolving it in a mixture of solvents to obtain the desired caprolactam compound of formula I.