4-Methylmorpholine → HCID 57071692, compound

Participants

Reaction Steps

0.8 g of 1-(di-p-anisylmethyl)-3-(1-p-nitrobenzyloxycarbonyloxyethyl)-4-carboxymethyl-2-azetidinone was dissolved in 20 ml of dried methylene chloride, and 0.17 ml of N-methylmorpholine was added thereto. After cooling to -10° C. or less, 0.15 ml of ethyl chloroformate was added dropwise thereto, followed by stirring for 30 minutes. Separately, 0.81 g of t-butyl-(p-nitrobenzyl) malonate was dissolved in 15 ml of dried tetrahydrofuran, and 0.14 g of sodium hydride (50% purity) was added to the resulting solution in a nitrogen stream under ice-cooling, followed by stirring at that temperature for 30 minutes. The resulting solution was added dropwise to the above prepared solution of a mixed anhydride at a temperature of -10° C. or less, followed by stirring for 1 hour. The reaction mixture was warmed to room temperature and concentrated under reduced pressure. The concentrate was diluted with cool water and ethyl acetate, washed successively with a 1N aqueous solution of hydrochloric acid and water, dried over sodium sulfate and distilled off to remove the solvent. The resulting residue was purified by silica gel chromatography to obtain 1-(di-p-anisylmethyl)-3-(1-p-nitrobenzyloxycarbonyloxyethyl)-4-[3-t-butoxycarbonyl-3-(p-nitrobenzyloxycarbonyl)-2-oxopropyl]-2-azetidinone.

Provenance & Evidence