反应详情

2,2,2-Trichloroethyl 7β-formamido-3-vinylceph-3-em-4-carboxylate (0.88 g., 2.3 mmole) was treated with dry methanol (5 ml.), when some solid crystallised. The suspension was cooled to ca. 5° and stirred while phosphorus oxychloride (0.53 ml.) was added dropwise. The reaction mixture was kept at ca. 5° for 30 minutes and diluted with ether (20 ml.); no solid separated. The solvents were evaporated and the residual oil was treated with ether (ca. 10 ml.) to give a white solid. The solid was filtered off, washed with ether, and dried to give the title hydrochloride (0.765 g., 85%), λmax. (MeOH) 295 nm (ε 10,150), νmax. (Nujol), ca. 2590 (N+H3), 1788 (azetidin-2-one), 1730 (CO2R), and 946 cm-1 (=CH2), τ (Me2SO-d6), 2.86 (1H, dd, J 11 and 17.5 Hz; CH=CH2), 4.13 (1 H, d, J 17.5 Hz) and 4.45 (1H, d, J 11 Hz) (CH=CH2), 4.64 (1H, d, J 5 Hz; C7 -H), 4.78 (1H, d, J 5 Hz; C6 -H), 4.81 and 4.98 (2H, AB-q, J 12 Hz; CH2CCl3), 5.92 and 6.24 (2H, AB-q, J 17 Hz; C2 -H2), 6.31 (ca 1H, d, JP-H 11 Hz; ca. 0.1 M trimethyl phosphate) (Found: P, 0.78%).

1. customcrystallised
2. temperatureThe suspension was cooled to ca. 5°
3. additionwas added dropwise
4. additiondiluted with ether (20 ml.)
5. customno solid separated
6. customThe solvents were evaporated
7. additionthe residual oil was treated with ether (ca. 10 ml.)
8. customto give a white solid
9. filtrationThe solid was filtered off
10. washwashed with ether
11. customdried