反应详情

A solution of t-butyl-3-acetoxymethyl-7β-(2-hydroxyiminopyrid-4-ylacetamido)-ceph-3-em-4-carboxylate (syn-isomer) (1.15 g) in tetrahydrofuran (20 ml) was treated with an excess of diazoethane at 20° for 40 minutes. The mixture was diluted with ether, washed with water and extracted with 2 N-hydrochloric acid. The aqueous extract was neutralised with saturated sodium bicarbonate solution and extracted with ethyl acetate. Evaporation of the dried organic extract offered the title ester as a foam (0.84 g, 69%), [α]D + 47° (c 0.84, DMSO), λmax. (EtOH) 259 nm (ε 15,450), νmax. (Nujol) 3300 (NH), 1788 (β-lactam), 1740 (OAc), 1724 (CO2R), 1678 and 1540 cm.-1 (CONH), τ (d6 -DMSO) values include 0.12 (d, J 8 Hz; NH), 1.26 and 2.42 (multiplets; aromatic protons), 5.69 (q, J 7 Hz, OCH2CH 3), 7.93 (s; OCOCH3), 8.50 (s; (CH3)3) and 8.69 (t, J 7 Hz; OCH2CH3).

1. washwashed with water
2. extractionextracted with 2 N-hydrochloric acid
3. extractionThe aqueous extract
4. extractionextracted with ethyl acetate
5. customEvaporation of the dried
6. extractionorganic extract
7. customthe title ester as a foam (0.84 g, 69%), [α]D + 47° (c 0.84, DMSO), λmax