Patent ID: 6353100
Filing Date: 2002-03-05
Classification: C07D

Abstract:
A process for preparing &egr;-caprolactam comprising:(a) contacting a compound having the formula: O=CHâ€”(CH2)4â€”C(O)â€”Râ€ƒâ€ƒ(1) wherein R is â€”OH, â€”NH2, or â€”Oâ€”Râ€², and wherein Râ€² is an alkyl, cycloalkyl, aryl or aralkyl group with 1 to 10 carbon atoms, in an aqueous medium as solvent, at an elevated pressure with ammonia and hydrogen in the presence of a hydrogenation catalyst to form a mixture of &egr;-caprolactam, 6-aminocaproamide, 6-aminocaproate ester, 6-aminocaproic acid and oligomers of said compounds, wherein the yield to &egr;-caprolactam in (a) is carried to a level of at least 10 molar %, calculated on the initial molar amount of said compound, and extracting &egr;-caprolactam from said aqueous mixture obtained from (a) with an organic extraction agent to form an organic extractant solution of &egr;-caprolactam and a separate residual aqueous mixture, followed by (b) reacting said 6-aminocaproamide, 6-aminocaproate ester, 6-aminocaproic acid and oligomers of said compounds in said residual aqueous mixture to form &egr;-caprolactam.