反应详情

Following a procedure analogous to that of Goldman et al. (loc. cit.), 7-aminodesacetoxycephalosporanic acid (7-amino-3-methylceph-3-em-4-carboxylic acid; 74.9 g., 0.35 mole) is dissolved in well-stirred water (200 ml.) by the slow addition of sodium hydroxide (approximately 75 ml. of 4 N) to a pH of 7.5. To this solution is added 200 ml. of acetone. Keeping the temperature at 10° to 15° C., the isopropyl ether solution of 2-phenyl-2-benzhydryloxycarbonylacetyl chloride prepared above is added with continued strong stirring over 3 minutes. The pH is maintained near 6.5 by the addition of 4 N NaOH (about 160 ml.). Organic solvents are removed by evaporation in vacuo. The aqueous layer is diluted with an equal volume of ethyl acetate and the pH adjusted to 2. The ethyl acetate layer is separated, washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to yield 7-(2-benzhydryloxycarbonyl-2-phenylacetamido)-3-methylceph-3-em-4 -carboxylic acid.

1. additionTo this solution is added 200 ml
2. customat 10° to 15° C.
3. additionabove is added
4. customOrganic solvents are removed by evaporation in vacuo
5. additionThe aqueous layer is diluted with an equal volume of ethyl acetate
6. customThe ethyl acetate layer is separated
7. washwashed with brine
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationfiltered
10. customevaporated in vacuo