| 摘要 |
1338266 3,4-Dihydroxyphenylalanine hemihydrochloride AJINOMOTO CO Inc 15 Oct 1971 [15 Oct 1970 31 Oct 1970 28 Dec 1970 30 Dec 1970] 48170/71 Heading C2C Novel 3,4 - dihydroxyphenylalanine hemihydrochloride in its DL-, L- and D-forms are prepared by preparing a supersaturated solution of the molecules in the correct proportions and allowing to crystallize. The D- and L-forms may also be crystallized from a supersaturated solution of the racemic form by seeding. The novel compounds may be used in a resolution process for obtaining D- or L-3, 4-dihydroxyphenylalanine and L- or D-3,4 dihydroxyphenylalanine hemihydrochloride which comprises preparing a solution of D, L-dopa and D, L-dopa ¢HCl supersaturated with respect to one of the compounds and seeding with seed crystals of one optically active enantiomorph of said first compound to form a first crop of crystals, then making the residual solution supersaturated with respect to the opposite enantiomorph of the other compound and seeding with seed crystals of said opposite enantiomorph of the other compound to form a second crop of crystals. |
