Methanol → HCID 131721639, compound

Participants

Reaction Conditions

Reaction Steps

4-Methoxybenzyl (6R, 7R) -7-phenylacetamido-3-[(2RS,3SR)-3-methyltetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (0.692g) in dry dichloromethane (5ml) under argon was cooled to -20° C. This solution was then treated with 4-methylmorpholine (0.268g, 0.291ml) followed by a solution of phosphorus pentachloride in dichloromethane (0.415g in 10.37ml) in a rapid dropwise fashion. The solution was allowed to warm to -5° C. and maintained at this temperature for 0.5h. Methanol (5ml) was then added in one portion and the solution allowed to warm to room temperature, and stirred for 0.5h. Water (5ml) was then added and the solution rapidly stirred for a further 0.75h. The dichloromethane was evaporated at reduced pressure and replaced with ethyl acetate. The pH was adjusted to 7.5 with aqueous 880 ammonia. The aqueous phase was extracted with ethyl acetate and the combined organic layers washed with brine and dried. Removal of solvent and column chromatography on silica gel eluting with 60 and then 70% ethyl acetate in hexane afforded the (2S,3R) isomer of the title compound as a pale yellow foam, (0.197g, 37%); vmax (CH2Cl2) 1777, 1720 and 1613cm-1 ; δH (CDCl3) 0.89 (3H, d, J 7.2Hz), 1.56 (1H, m), 2.14 (1H, m), 2.73 (1H, m), 3.37 and 3.57 (2H, ABq, J 18.0Hz), 3.73 (1H, m), 3.82 (3H, s), 4.05 (1H, m), 4.79 (1H, d, J 4.8Hz), 4.93 (1H, d, 4.8Hz), 4.98 (1H, d, J 7.6Hz), 5.17 (2H, s), 6.88 (2H, d, J 8.6Hz) and 7.33 (2H, d, J 8.6Hz). [Mass spectrum: +ve ion (3-nitrobenzyl alcohol, sodium acetate) MH+ (405), MNa+ (427)].

Provenance & Evidence