Patent ID: 7307184

Claim:
A process of starting from a N-alkoxycarbonyl-ethylamine compound having a leaving group at the β-position to prepare an oxazolidinone derivative of a β-hydroxyethylamine compound having an inverted steric configuration at the β-position carbon, which comprises: converting the N-alkoxycarbonyl-ethylamine compound having a leaving group at the β-position into an oxazolidinone derivative of a β-hydroxyethylamine compound having an inverted steric configuration at the β-position carbon under non-aqueous conditions, whereby a by-product L-R 0 is secondarily produced from the leaving group (L) and the monovalent organic group (R 0 ) in the alkoxycarbonyl group (—COOR 0 ) present in the N-alkoxycarbonyl-ethylamine, and then carrying out a step of treating in contact with water in a molar amount above 5-fold with heating to above 40° C. under acidic to neutral conditions, whereby the by-product L-R 0 is made harmless.