反应详情

A solution of triphenylphosphine (1.06 g, 2 equiv.) in ethyl acetate (5 ml) was added to a stirred solution of 2,2,2-trichloroethyl 3-bromomethyl-7β-formamidoceph-3-em-4-carboxylate (0.91 g, 2 mmole) in ethyl acetate (5 ml). The mixture was stirred at ca. 20° for 45 minutes and then warmed to 45° for 10 minutes. The precipitated solid was filtered off, washed with ethyl acetate and ether, and dried to give the title phosphonium salt (1.06 g, 74%), m.p. 151° to 153° (dec.), [α]D + 92° (C 1.0; CHCl3), λmax. (EtOH) 268.5 nm (ε 9,000) and 275 nm (ε 9,000), νmax. (CHBr3) 3430 (NH), 1795 (azetidin-2-one), 1730 (CO2R), 1700 (CONH) and 1445 cm-1 (P+ -C6H5), 0.91 (1H,d, J9 Hz; NH), 4.25 (1H,dd, J 9 and 5 hz; C7 -H), 4.67 (1H,d, J 5 Hz; C6 -H), 4.77 and 4.93 (2H, centers of two collapsed AB-quarters, JP-H 16 Hz; C3 -CH2P+), 5.25 and 5.45 (2H, AB-q, J 12 Hz; CH2CCl3) (Found: C, 46.9; H, 3.7; N, 3.7; P, 3.7; S, 3.9%; total halogen content, 3.9 equiv./mole compound. C29H25BrCl3N2O4PS (714.9) requires C, 48.7; H, 3.5; N, 3.9; P, 4.3; S, 4.5%; total halogen content 4 equiv./mole compound).

1. temperaturewarmed to 45° for 10 minutes
2. filtrationThe precipitated solid was filtered off
3. washwashed with ethyl acetate and ether
4. customdried