An N-acyl-substituted or unsubstituted phenylalanine is prepared by hydrolyzing a 2-substituted-4-substituted or unsubstituted benzylidene-5-oxazolone with an alkali, adjusting the reaction system containing its hydrolysis product with acid to a pH of 5 - 9 and reducing the resultant reaction solution catalytically in the presence of a palladium or platinum reducing catalyst. The reduction is carried out continuously without isolating the alkaline hydrolysis product, i.e., a substituted or unsubstituted N-acylaminocinnamic acid from the reaction system.
The catalyst can be recovered after completion of the reduction and used repeatedly without additional treatment and without any observed lowering in its catalytic activity. Accordingly, the reductions using the recovered catalyst may proceed at pratically the same rate as reductions using a fresh catalyst.
Raghunathan, R.; Naidu, P. V. Rajagopal, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1989, vol. 28, # 1-11, p. 966 - 967
作者:Raghunathan, R.、Naidu, P. V. Rajagopal
DOI:——
日期:——
Action of Grignard Reagents. XXIII. Action of Organomagnesium Compounds on Saturated and Unsaturated Azlactones. Addition Reactions of Mercaptans and Piperidine with Unsaturated Azlactones