反应详情

Aluminium chloride (740mg, 5.55mmol) was added to anisole (32ml) and dry dichloromethane (15ml) at -20° C. and stirred for 15 min. The temperature of the cooling bath was then lowered to -40° C. before addition of a solution of 4-methoxybenzyl (6R,7R)-7-[2-(2-aminothiazol-4-yl)-2-(Z)-methoxyiminoacetamido]-3-[(R)-tetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (1.06 g, 1.85 mmol) in dichloromethane (10ml). After 10 min., the solution was treated with trisodium citrate (0.5M, 54ml) and then vigorously stirred for 10 min. at room temperature. The aqueous phase was separated, washed with dichloromethane (x2) and concentrated in vacuo. The residue was chromatographed on HP20SS eluting with water, then 1% THF in water. Fractions containing the product, (h.p.l.c. analysis), were combined and freeze-dried to give the title compound (560mg, 64%); vmax (KBr) 3399, 1762, 1669, 1603, 1529, 1038cm-1 ; δH (d6 -DMSO, 250MHz) 1.50-1.91 (4H, m), 3.25 and 3.38 (2H, ABq, J 16.8Hz), 3.60-3.82 (2H, m), 3.84 (3H, s), 4.96 (1H, d, J 4.7Hz), 5.20 (1H, dd, J 8.6, 6.0Hz), 5.48 (1H, dd, J 8.1, 4.7Hz), 6.76 (1H, s), 7.23 (2H, br. s, exch.), 9.50 (1H, d, J 8.1Hz, exch.). [Mass spectrum: +ve ion (thioglycerol) MH+ (476), MNa+ (498)].

1. waitAfter 10 min.
2. stirringvigorously stirred for 10 min. at room temperature
3. customThe aqueous phase was separated
4. washwashed with dichloromethane (x2)
5. concentrationconcentrated in vacuo
6. customThe residue was chromatographed on HP20SS
7. washeluting with water
8. additionFractions containing the product, (h.p.l.c. analysis),
9. customfreeze-dried