RESOLUTION, CRYSTAL-STRUCTURE AND ABSOLUTE-CONFIGURATION OF THE ENANTIOMERS OF AMINOPHENYLMETHANEPHOSPHONOUS ACID HYDRATE

Enantiomers of aminophenylmethanephosphonous acid have been obtained b y resolution of the racemic acid using optically active isomers of l-p henylethylamine. The crystal and molecular structures of the enantiome rs of the acid monohydrate (C7H10PO2N . H2O) have been determined by s ingle-crystal X-ray diffraction method. The crystals are monclinic, of space grup P2(1)2(1)2(1) and Z = 4. Cell constants: a = 5.410(2) Angs trom, b = 6.603(2) Angstrom, c = 25.061(5) Angstrom for (+)-(R)-enanti omer and a = 5.414(2) Angstrom, b = 6.602(2) Angstrom, c = 25.056(5) A ngstrom for (-)-(S)-enantiomer. The structures solved by direct method have been refined to final R = 0.033 and R = 0.029 respectively.