Methyl 4-chloro-3-hydroxybutanoate

In 10 ml of ethanol, 1.11 g (10 m.moles) of glycinamide hydrochloride, 1.06 g (10 m.moles) of sodium carbonate, and 1.53 g (10 m.moles) of methyl 4-chloro-3-hydroxybutyrate were stirred and refluxed simultaneously for 20 hours. After completion of the reaction, the warm reaction mixture was filtered to expel inorganic salts. The filtrate was analyzed by gas chromatography (Fluoxylate-K 1% Uniport HP 100/120, column length 0.5 m and column temperature 220° C., RT 2.8 min) (hereinafter referred to as "GC" for short). Consequently, the reaction was found to have produced oxiracetam in a yield of 75%. The filtrate was concentrated, dissolved in a small amount of water, and poured on a bed of 40 ml of Amberlite IR-120 (--SO3H form) (tradename: Rohm & Haas Co.). The adsorbate was eluted with water. The eluate was fractionated, with the first and second fractions discarded and the third and following fractions were collected. The collected fractions were concentrated. The concentrate was dissolved in methanol and the solution was ice cooled ad crystallized with crystals of oxiracetam used as mother crystals. The produced crystals were collected and vaccum dried, to afford 0.55 g (yield of isolation 35%) of oxiracetam, having a melting point of 155° to 160° C. (as compared with 161° to 163° C. reported in the specification of Japanese Patent Publication Sho 58-22,034/1983).