反应详情

To 8 ml. of dry acetonitrile were added 422 mg. (1 mmole) of 7-(α-amino-4-hydroxyphenylacetamido)-3-carbamoyloxymethyl-3-cephem-4-carboxylic acid. The mixture was stirred in a bath comprising acetone and wet ice, and 1.62 grams (8 mmoles) of N,O-bis-trimethylsilylacetamide were added. Solution was complete within about 5 minutes. The mixture was stirred for an additional 5 minutes, and 0.7 ml. of propylene oxide was added followed, after an additional 5 minutes, by 197 mg. (1 mmole) of 2,3-dihydro-2-oxo-1H-benzimidazol-1-ylcarbonyl chloride. The mixture was stirred for 105 minutes and then was rotary evaporated to about one-half volume. The concentrated reaction mixture was slowly added to rapidly-stirred ice water, and the pH of the resulting mixture, containing a percipitated gum, was adjusted from 3.8 to 1.6. The resulting mixture then was sonicated, with hardening of the gum. The resulting hard lumps were broken, sonicated, filtered, washed with dilute hydrochloric acid (pH 1.8), and air-dried to give 251 mg. of a buff powder. The filtrate was concentrated to remove acetonitrile and was filtered to afford an additional 20 mg. of a buff-colored powder. The solids were combined and added to 40 ml. of methylene chloride. The mixture was sonicated and filtered to recover 210 mg. of solid. The solid was added to 100 ml. of methylene chloride, sonicated, and filtered to obtain 200 mg. of the title compound.

1. additionwere added
2. waitfollowed, after an additional 5 minutes, by 197 mg
3. stirringThe mixture was stirred for 105 minutes
4. customwas rotary evaporated to about one-half volume
5. customThe concentrated reaction mixture
6. additionwas slowly added
7. additionthe pH of the resulting mixture, containing a percipitated gum
8. customThe resulting mixture then was sonicated, with hardening of the gum
9. customsonicated
10. filtrationfiltered
11. washwashed with dilute hydrochloric acid (pH 1.8)
12. customair-dried
13. customto give 251 mg
14. concentrationThe filtrate was concentrated
15. customto remove acetonitrile
16. filtrationwas filtered
17. customto afford an additional 20 mg
18. additionadded to 40 ml
19. customThe mixture was sonicated
20. filtrationfiltered
21. customto recover 210 mg
22. additionThe solid was added to 100 ml
23. customof methylene chloride, sonicated
24. filtrationfiltered
25. customto obtain 200 mg