Patent ID: 7598422
Filing Date: 2009-10-06
Classification: C07B,C07C,C07D

Abstract:
1. A method of selectively preparing a chiral amino alcohol useful in preparation of an amine sulfonated or acylated with a residue containing an alkyl, substituted aryl or substituted heteroaryl group, said method comprising the steps of: (a) reacting di-tert-butyl azodicarboxylate with an anion derived from (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-(1S,2S)-([(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate; (b) reducing the di-tert-butyl 1-(1S,2S)-(1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate of (a) to yield di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate; (c) deblocking the product of (b) with an acid to yield the acid addition salt of (2S,3S)-trifluoro-hydrazino-methyl alkan-1-ol; and (d) hydrogenating the acid addition salt of (2S,3S)-trifluor-2-hydrazino-methyl alkan-1-ol in the presence of suitable metal catalyst to yield the amino alcohol (2S,3S)-2-Amino-trifluoro-methyl alkan-1-ol HCl.