| 摘要 |
PURPOSE:A beta-lactam is hydrogenolyzed in the presence of a palladium catalyst to produce the title compound used as a remedy for Partkinson's diseases from an inexpensive starting material through shortened process in high yield. CONSTITUTION:In the presence of a palladium catalyst, the hydrogenolysis of a beta- lactam of formula I (R<1>, R<2> are H, alkyl, benzyl, acyl and they may incorporate to form alkylene; R<3> is alkyl, aryl, aromatic heterocycle; X is amino, azide) is effected to produce a dopa derivative of formula II. As the palladium catalyst, Pd-C is preferred, because the palladium metal is well dispersed and it is high effective even in a small amount and the amount is usually 1-50% based on the beta-lactam (calculated as palladium metal). The reaction pressure is preferably 1-20 atmospheric one, because it is easy-to-operate. |
