反应详情

To 3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylic acid (syn-isomer) (5.0 g) was added sufficient saturated sodium bicarbonate solution to bring the pH to 7.0, during which time solution occurred. To this solution was added water (300 ml.) and defatted wheat germ (35 g.), and the suspension stirred vigorously whilst the pH was maintained at between 6.7 and 6.9 by frequent additions of 2 N-sodium hydroxide. After addition of ca. 6 ml, the pH remained constant at 6.9. The mixture was poured into acetone (400 ml.), filtered (kieselguhr), and the filtrate evaporated under reduced pressure to remove acetone, then refiltered (kieselguhr). The filtrate was washed with ethyl acetate, and the pH adjusted to 2.8. The aqueous phase was extracted with ethyl acetate, and the extracts were stirred with water (ca. 300 ml.) and the pH brought up to 7.0 with 2 N sodium hydroxide. Th phases were separated and the aqueous phase washed twice with ethyl acetate, once with ether, evaporated under reduced pressure to remove residual solvents, and freeze-dried. This gave the title acid (1.5 g: 31%), [α]D +93° (c 1.0, DMSO), λmax. (pH 6 phosphate buffer) 252 nm (ε 12,800), νmax. (Nujol) 1750 (β-lactam), 1650 and 1530 cm.-1 (amide), τ (DMSO-d6) values include 2.3 to 2.6 (multiplet; aromatic protons), 5.72 and 6.05 [two doublets (branches of a quartet), J 13 Hz; CH2OH], 6.44 and 6.68 [two doublets (branches of a quartet), J 18 Hz; C-2CH2 ].

1. additionAfter addition of ca. 6 ml
2. filtrationfiltered (kieselguhr)
3. customthe filtrate evaporated under reduced pressure
4. customto remove acetone
5. washThe filtrate was washed with ethyl acetate
6. extractionThe aqueous phase was extracted with ethyl acetate
7. stirringthe extracts were stirred with water (ca. 300 ml.)
8. customTh phases were separated
9. washthe aqueous phase washed twice with ethyl acetate, once with ether
10. customevaporated under reduced pressure
11. customto remove residual solvents
12. customfreeze-dried
13. customThis gave the title acid (1.5 g: 31%), [α]D +93° (c 1.0, DMSO), λmax