Cesium carbonate → HCID 67525379, compound

Participants

Reaction Steps

To the obtained solution of (1R*,6R*)-3-oxo-6-phenyl-4-oxa-2-aza-bicyclo[4.1.0]heptan-1,2-dicarboxylic acid di-t-butyl ester (2.1 g, 5.5 mmol) in methanol (42 mL) was added cesium carbonate (0.54 g, 1.7 mmol) at room temperature. After stirring for 30 min., the mixture was concentrated to about half the amount under reduced pressure, and then saturated aqueous sodium chloride solution (40 mL) was added to the obtained residue. The mixture was extracted three times with ethyl acetate (30 mL), washed with water (50 mL) and saturated aqueous sodium chloride solution (50 mL), and dried over sodium sulfate. After filtration and evaporation, hexane (20 mL) was added to the obtained residue to allow precipitation of crystals. The crystals were filtrated and dried under reduced pressure to give the title compound (1.9 g, yield 74%) as a colorless amorphous form.

Provenance & Evidence