Water → HCID 66672660, compound

Participants

Reaction Steps

(4R)-4-Methyl-4-[2-(1-methylpyrrol-2-yl)ethyl]-1,3-oxazolidin-2-one (17.9 g, 86.0 mmol) obtained in Reference example 1 (1f) was dissolved in a mixture of tetrahydrofuran (250 mL) and methanol (125 mL) and a 5N aqueous potassium hydroxide solution (125 mL) was added thereto, followed by heating under reflux of the mixture for 4 days. After cooling, water and methylene chloride were added to the reaction mixture to separate it. The thus obtained organic phase was separated and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced-pressure and the residue was dissolved in ethanol (260 mL). D-(−)-tartaric acid (6.45 g, 43.0 mmol) was added thereto and the mixture was stirred for 2 hours. The precipitated crystal was collected by filtration to obtain a crude crystal (20.7 g). The crude crystal (18.7 g) was recrystallized from a mixture of ethanol (370 mL) and water (37 mL) and the thus obtained crystal was recrystallized again from a mixture of ethanol (300 mL) and water (30 mL). Further, the obtained crystal was recrystallized again from a mixture of ethanol (240 mL) and water (24 mL) to obtain the title compound (10.5 g, yield: 53%) as a colourless scaly crystal.

Provenance & Evidence