反应详情

温度

20 °C

3-Acetoxymethyl-7-amino-2(t-butoxycarbonyl)-8-oxo-5-thia-1-aza-bicyclo[4,2,0]oct-2-ene (11.2 g.) and dicyclohexylcarbodiimide (7.8 g.) are added to a solution of (5,6-dihydro-1,4-dithiin-2-yl)acetic acid (6 g.) in dimethylformamide (50 cc.). The reagents are left in contact for 5 hours, with stirring, at a temperature of about 20° C. and then the solid is filtered off. The filtrate is taken up in ethyl acetate (300 cc.) and is washed with an aqueous solution of sodium bicarbonate, N hydrochloric acid and then with water. After drying over sodium sulphate, it is treated with decolourizing charcoal and concentrated to dryness under reduced pressure (20 mm.Hg). A residue (20 g.) is obtained and is chromatographed on silica (330 g.). Elution is effected using a mixture (10 liters) of ethyl acetate and cyclohexane (1-3 by volume), and the eluates are concentrated to dryness under reduced pressure (20 mm.Hg). 3-Acetoxymethyl-2-(t-butoxycarbonyl)-7-[(5,6-dihydro-1,4-dithiin-2 -yl)acetamido]-8-oxo-5-thia-1 -aza-bicyclo-[4,2,0]oct-2-ene (10.3 g.), melting at 80° C., is thus obtained.

1. filtrationthe solid is filtered off
2. washis washed with an aqueous solution of sodium bicarbonate, N hydrochloric acid
3. dry with materialAfter drying over sodium sulphate, it
4. additionis treated with decolourizing charcoal
5. concentrationconcentrated to dryness under reduced pressure (20 mm.Hg)
6. customA residue (20 g.) is obtained
7. customis chromatographed on silica (330 g.)
8. washElution
9. concentrationthe eluates are concentrated to dryness under reduced pressure (20 mm.Hg)