反应详情

5.00 g (10.1 mmol) of Diphenylmethyl 7-tert-butoxycarbonylamino-3-hydroxymethyl-3-cephem-4-carboxylate, 7.93 g (30.2 mmol) of triphenylphosphine, and 7.28 g (60.2 mmol) of p-methoxyphenol were dissolved in 25 ml of tetrahydrofuran under argon atmosphere, and the reaction solution was cooled to -40°-35° C., and 4.76 ml (30.2 mmol) of diethyl azodicarboxylate were added dropwise, and then the stirring was effected for 6 hrs. at the same temperature. This solution was added to a suspension of 300 ml of ice cold 1N hydrochloric acid and 300 ml of ethyl acetate, and stirred, and then separated, and the layer of ethyl acetate was washed with water and saturated saline solution, and dried over anhydrous magnesium sulfate. Benzene was added to a caramel obtained by evaporating off the solvent so that the insoluble material was removed by filtering off, and the residue obtained by evaporating off the benzene filtrate was dissolved in diethyl ether. This ether solution was washed with 20% potassium carbonate aqueous solution until unreacted p-methoxyphenol was removed, and further washed with saturated potassium dihydrogen phosphate aqueous solution, water, and saturated saline solution. The layer of ether was dried over anhydrous magnesium sulfate, and then, ether was evaporated off to give 2.80 g of a caramel. The caramel was column chromatographed on silica gel by eluting with benzene-acetone (V:V;100:1), and then, powdered with ether-hexane to give 1.29 g of diphenylmethyl 7-tert-butoxycarbonylamino-3-(4-methoxyphenoxymethyl)-3cephem-4-carboxylate.

1. temperaturethe reaction solution was cooled to -40°-35° C.
2. customseparated
3. washthe layer of ethyl acetate was washed with water and saturated saline solution
4. dry with materialdried over anhydrous magnesium sulfate
5. additionBenzene was added to a caramel
6. customobtained
7. customby evaporating off the solvent so that the insoluble material
8. customwas removed
9. filtrationby filtering off
10. customthe residue obtained
11. customby evaporating off the benzene filtrate
12. dissolutionwas dissolved in diethyl ether
13. washThis ether solution was washed with 20% potassium carbonate aqueous solution until unreacted p-methoxyphenol
14. customwas removed
15. washfurther washed with saturated potassium dihydrogen phosphate aqueous solution, water, and saturated saline solution
16. dry with materialThe layer of ether was dried over anhydrous magnesium sulfate
17. customether was evaporated off
18. customto give 2.80 g of a caramel
19. customchromatographed on silica gel
20. washby eluting with benzene-acetone (V:V;100:1)