Patent ID: 7385080

Claim:
A method for making an optically active N-acyl-β-phenylalanine compound represented by formula (4): wherein R 1 is hydrogen atom, halogen atom, nitro group, a C 1-6 alkyl group, or a C 1-6 alkoxy group; a is an integer of from 1 to 5; R 2 is hydrogen atom, a C 1-6 alkyl group, a C 6-10 aryl group, or a C 7-11 aralkyl group; and * means that that carbon atom is an asymmetric carbon atom, said method comprising: (a) reacting an N-acyl-β-phenylalanine compound represented by formula (1): wherein R 1 , a, and R 2 are as defined above, with either an optically active compound represented by formula (2): wherein R 3 and R 4 each independently is hydrogen atom, halogen atom, nitro group, a C 1-6 alkyl group, or a C 1-6 alkoxy group; b and c are each independently an integer of from 1 to 5; and * has the same meaning as defined above, or an optically active compound represented by formula (3): wherein R 3 , R 4 , b and c, and * have the same meanings as defined above, to obtain a diastereomer salt; (b) subjecting said diastereomer salt to an optical resolution, to obtain an optically active diastereomer salt; and (c) subjecting said optically active diastereomer salt to a double decomposition treatment, to obtain said optically active N-acyl-β-phenylalanine compound represented by formula (4).