Dichloromethane → HCID 12774965, compound

Participants

Reaction Steps

To a solution of diphenylmethyl 7α-phenylacetamido-3-methyl-3-cephem-4-carboxylate (2.88 g, 5.8 mmol) in 40 ml of methanol and 60 ml. of methylene chloride, was added N-chlorosuccinimide (882 mg, 6.6 mmol) and the mixture was stirred for 90 minutes at room temperature. The reaction solution was then washed with brine (2X), dried over magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure. The resultant yellow foam (2.84 g) was chromatographed over 100 grams of silica gel employing 10-15% of ethyl acetate in toluene as the eluting solvent. The first fraction to elute from the column was the desired 2α-methoxy cephem compound which was subsequently recrystallized from a mixture of ethyl acetate and cyclohexane to give pure diphenylmethyl 7α-phenylacetamido-2α-methoxy-3-methyl-3-cephem-4-carboxylate. (638 mg, 21% yield) (mp 144°-145° C.) i.r. (CHCl3) 1780, 1725 and 1680 cm-1 ; n.m.r. (CDCl3 ) δ1.95 (s, 3, CH3) 3.35 (s, 3, OCH3), 3.45 (s, 2, CH2Ph), 4.60 (s, 1, C2 --H), 4.70 (d, J=2 and 8 Hz, 1, C7 --H), 4.85 (d, J=2 Hz, 1, C6 --H) 6.95 (s, 1, CH2Ph), 7.3 (m, 16, aromatic and N--H); u.v. (CHCl3) λmax 264 nm (ε=9726).

Provenance & Evidence