Patent ID: 8017378

Claim:
A method for producing an optically active biphenylalanine compound of the formula (2): wherein, R 2 is a protective group of an amino group, and R 3 and R 4 are each independently a hydrogen atom, a halogen atom, an alkyl group, a haloalkyl group, a hydroxyl group, an alkoxy group, a cyano group, or a nitro group or a salt thereof and an optically active biphenylalanine ester compound of the formula (3): wherein, R 1 is an alkyl group, a haloalkyl group, an alkenyl group, a cycloalkyl group, an aryl group being optionally substituted, or an aralkyl group being optionally substituted; and R 2 , R 3 and R 4 have the same meanings as described above which comprises the step of hydrolyzing a biphenylalanine ester compound of the formula (1): wherein, R 1 , R 2 , R 3 and R 4 have the same meanings as described above with protease produced by a microorganism belonging to Bacillus sp. in the presence of at least one alkali selected from an alkali metal hydroxide and an alkaline earth metal hydroxide.