Benzyl glyoxylate → 7-(Benzyloxycarbonyl-1-hydroxymethyl)-3-phenoxymethyl-6-oxo-2-thia-4,7-diazabicyclo[3,2,0]hept-3-ene

Participants

Reaction Steps

Into a 500 ml. flask equipped with a Dean-Stark condenser filled with Molecular Sieves 3A (™, manufactured by Nakarai Chemicals Ltd.) were charged with 3-phenoxymethyl-6-oxo-2-thia-4,7-diazabicyclo[3,2,0]hept-3-ene (995 mg.), benzyl glyoxylate (6.2 g.) and benzene (80 ml.). The mixture was heated under reflux for 3.5 hours. After benzene (40 ml.) was distilled off, the resultant solution was cooled to room temperature, and 25% aqueous solution of sodium bisulfite (150 ml.) was added thereto. The mixture was stirred for half an hour, and the precipitate was filtered off and washed with benzene. The organic layer was separated and washed twice with water (50 ml.) and twice with an aqueous solution of sodium chloride (150 ml.). Drying over magnesium sulfate and removal of the solvent gave an oil (8.7 g.) of 7-(1-benzyloxycarbonyl-1-hydroxymethyl)-3-phenoxymethyl-6-oxo-2-thia-4,7-diazabicyclo[3,2,0]hept-3-ene.

Provenance & Evidence