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 (2×), 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. (CDCl 3) δ 1.95 (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