Patent ID: 6084123
Filing Date: 2000-07-04
Classification: C07F

Abstract:
A process for the preparation of an optically active (R)- or (S)-1-aminophosphonic acid derivative represented by the general formula (Ia) or (Ib): ##STR44## wherein R.sup.2 has the same meaning as given below, characterized in that the process comprises the following steps:reacting an imine represented by the general formula (II):R.sup.1 --N.dbd.CHR.sup.2 (II)wherein R.sup.1 stands for diphenylmethyl group or an alkoxyphenyl group and R.sup.2 stands for an alkyl group or a cycloalkyl group, or an aryl group-containing hydrocarbon radical, or R.sup.2 stands for an aryl group optionally substituted with a halogen atom or an alkoxy group, with a phosphonic acid ester represented by the general formula (III): ##STR45## wherein R.sup.3 stands for an alkyl group, a cycloalkyl group, allyl group or an aryl group or an aryl group-containing hydrocarbon radical, in the presence of an asymmetric catalyst consisting of a rare earth element-alkali metal-binaphthol complex to produce a (R)- or (S)-N-protected-1-aminophosphonate compound represented by the general formula (IVa) or (IVb): ##STR46## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meanings as defined above;subjecting the compound of the formula (IVa) or (IVb) to catalytic reduction with hydrogen to eliminate the amino-protecting group R.sup.1 therefrom to produce a (R)- or (S)-1-aminophosphonic acid ester represented by the formula (Ia') or (Ib'): ##STR47## wherein R.sup.3 has the same meaning as defined above; and subjecting the resulting compound of the formula (Ia') or (Ib') to acidic hydrolysis to eliminate the ester-forming group R.sup.3 therefrom.