公开(公告)号：BE745034A

公开(公告)日：1970-07-28

申请号：BE745034D

申请日：1970-01-28

Applicant: HOFFMANN LA ROCHE

Inventor： BROSSI A ,  HEVERAN J E ,  SENKOWSKI E A MACMULLANET B Z

IPC: C07C227/40 ,  A61K31/195 ,  C07C229/36 ,  C07G

Abstract: 1,266,812. Purification of L-Dopa. F. HOFFMAN LA ROCHE & CO. A.G. 14 Jan., 1970 [31 Jan., 1969], No. 1757/70. Heading C2C. Optically and/or chemically pure L-Dopa is prepared by a process comprising steps (a) and/or (b) below; said step (a) comprising mixing crystalline L-Dopa having at most 18% by weight of D-Dopa entrained therein into a solvent mixture comprising from about 40% to 60% by volume of water and from about 40% to 60% by volume of methanol or ethanol to dissolve all of the D-Dopa and separating the L-Dopa from the solvent mixture as a crystalline material substantially free of D-Dopa, and said step (b) comprising dissolving crystalline L-Dopa having chemical impurities entrained therein in an aqueous solution containing ascorbic acid at a temperature of at least 80‹ C. and crystallizing the L-Dopa from the aqueous solution to produce crystalline L-Dopa substantially free from all chemical impurities; in the ease of a two-step process said steps (a) and (b) being carried out in any desired order.