Methanol → HCID 56985057, compound

Participants

Reaction Conditions

Reaction Steps

Phosphorus pentachloride (754mg, 3.62mmol) in dichloromethane (19ml) was added to 4-methoxybenzyl (6R,7R)-3-(5-methyltetrahydrofuran-2-yl)-7-phenylacetamidoceph-3-em-4-carboxylate (containing some of the Δ2-isomer) (1.26g, 2.41mmol) and N-methylmorpholine (531gl, 4.83mmol) in dichloromethane (15ml) at -25° C. The reaction was stirred at -10±5° C. for 45 min., then methanol (5ml) was added, and stirring was continued for 45 min. at room temperature. Water (10ml) was then added, and the mixture vigorously stirred for a further 1h. After evaporation of the dichloromethane in vacuo, the pH of the aqueous residue was adjusted to 7 by the addition of ammonium hydroxide in the presence of ethyl acetate. The mixture was extracted with ethyl acetate (x2), dried and concentrated in vacuo. The residue was purified by chromatography on silica gel eluting with 30, 50, 70, 80 and 100% ethyl acetate in hexane yielding 4-methoxybenzyl (6R,7R)-7-amino-3-[(5S,2S)-5-methyltetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (310mg, 32%) as a pale yellow foam; (Found: M+, 404.1394. C20H24N2O5S requires M+ 404.1406); vmax (CH2Cl2) 3412, 1776, 1721, 1613, 1516 and 1393cm -1 ; δH (CDCl3, 250MHz), 1.24 (3H, d, J 5.8Hz), 1.48 (1H, m), 1.69 (1H, m), 2.02 (3H, m, 2H exch.), 2.25 (1H, m), 3.45 and 3.60 (2H, ABq, J 17.7Hz), 3.78 (3H, s), 3.98 (1H, m), 4.88 (1H, d, J 5.0Hz), 4.93-5.04 (2H, m), 5.17 (2H, s), 6.87 (2H, d, J 8.6Hz), 7.32 (2H, d, J 8.6Hz).

Provenance & Evidence