Phosphoric Acid → HCID 70504140, compound

Participants

Reaction Steps

A 6.8 ml portion of pyridine was added to a solution of 4 g of diphenylmethyl 7-(2-thienylacetamido)-2β-methyl-3-acetoxymethylceph-3-em-4-carboxylate in 170 ml of CH2Cl2, and 4.35 g of PCl5 was then added to the mixture at -12° C., followed by stirring at the same temperature for 45 minutes. 45 ml of MeOH was added in once to the mixture, followed by stirring at -10° C. for 30 minutes and further at room temperature for 1 hour. 100 ml of 0.5M K2HPO4 solution and further 25% H3PO4 were added to the reaction solution to adjust to pH 1.5, followed by stirring for 45 minutes and separating out the CH2Cl2 layer. The layer was washed with saturated aqueous NaCl solution and dried over MgSO4, and the CH2Cl2 was distilled off under reduced pressure. The residue was added on a column of silica gel, and the fractions eluted with CH2Cl2.AcOEt (10:1) were collected to distill off the solvent under reduced pressure. Petroleum ether was added to the residue, thus yielding 3.7 g (87%) of crystals of diphenylmethyl 7-amino-2β-methyl-3-acetoxymethylceph-3-em-4-carboxylate,

Provenance & Evidence