Benzaldehyde → Ethyl phenylglycinate, D-

Reaction equation

[CH3:1][CH2:2][O:3][C:4]([CH:6]([NH2:13])[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=[O:5].C(O)(=O)C(C(C(O)=O)O)O.C(=O)C1C=CC=CC=1>C(O)C>[CH3:1][CH2:2][O:3][C:4]([C@H:6]([NH2:13])[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=[O:5]

Participants

Procedure

A mixture of ethyl DL-phenylglycinate (5.021 g., 96% pure i.e. 27.0 mmole) and (+)-tartaric acid (2.027 g., 13.5 mmole, 0.5 equiv.) in ethanol (47 ml.) and benzaldehyde (2.75 ml., 2.88 g., 27.1 mmole, 1 equiv.) was stirred at 20°; crystallisation began within 5 minutes. After 10 days the mixture was filtered and the product washed with ethanol (2 × 7 ml.) and dried at 20°/4 mm. for 3 hours giving ethyl D-phenylglycinate (+)-hemitartrate solvated with 1.0 mole ethanol (3.922 g., 39% yield based on ester present or 78 % yield based on (+)-tartaric acid present), [α]D21 - 45.9° (c 2.506, H2O).