反应详情

[7β-Phenylacetamido-4-(2,2,2-trichloroethoxycarbonyl)ceph-3-em-3-ylmethyl]-triphenylphosphonium bromide (403 mg, 0.5 mmole) was dissolved in N,N-dimethylformamide (10 ml.) and 40% -formaldehyde solution (3 ml.) was added. The solution was stirred vigorously while a solution of disodium hydrogen phosphate (400 mg.) in water (5 ml.) was added dropwise. A white crystalline solid, subsequently identified as the title ester, separated before the addition was complete. The reaction mixture was diluted with chloroform (25 ml.) and water (10 ml.), whereupon the solid dissolved. The aqueous phase was re-extracted with chloroform (25 ml.), and the combined organic phases were washed with 2N-hydrochloric acid (50 ml.) and water (4 × 25 ml.), dried (MgSO4), and evaporated to give the title ester as a pale-yellow solid (128 mg., 54%), λmax. (EtOH) 297 nm (ε13,700). Crystallisation by trituration with ethanol (2 ml.) gave a white solid (75 mg., 31.5%, m.p. 163 to 165°, [α]D 23 - 54° (C 1.15; Me2SO), λmax. (EtOH) 297 nm (ε13,550), νmax. (CHBr3) 3410 (NH), 1772 (azetidin-2-one), 1730 (CO2R), 1674 and 1500 (CONH) and 912 cm-1 (=CH2), τ(CDCl3) 2.68 (5H, s; C6H5), 2.84 (1H, dd, J 11 and 18 Hz; CH=CH2), 3.61 (1H, d, J 8 Hz; NH), 4.13 (1H, dd, J 8 and 5 Hz; C7 --H), 4.48 (1H, d, J 18 Hz) and 4.60 (1H, d, J 11 Hz) (CH=CH2), 4.98 (1H, d, J 5 Hz; C6 --H), 4.99 and 5.25 (2H, AB-q, J 12 Hz; CH2CCl3), 6.30 and 6.53 (2H, AB,-q J 18 Hz; C2 --H2), 6.37 (2H, s; C6H5CH2) (Found: C, 46.8, 47.1; H, 3.6; Cl, 21.8; N, 5.5, 5.5; S, 6.5. C19H17Cl3N2O4S (475.8) requires C, 48.0; H, 3.6; Cl, 22.4; N, 5.9; S, 6.7%).

1. additionwas added dropwise
2. customseparated before the addition
3. additionThe reaction mixture was diluted with chloroform (25 ml.) and water (10 ml.), whereupon the solid
4. dissolutiondissolved
5. extractionThe aqueous phase was re-extracted with chloroform (25 ml.)
6. washthe combined organic phases were washed with 2N-hydrochloric acid (50 ml.) and water (4 × 25 ml.)
7. dry with materialdried (MgSO4)
8. customevaporated