反应详情

温度

20 °C

Thionyl chloride (3 cc.) is added to a solution of (5,6-dihydro-1,4-dithiin-2-yl)acetic acid (3.10 g.) in benzene (60 cc.), and the mixture is heated under reflux until gas ceases to be evolved. The reaction mixture is then concentrated to dryness under reduced pressure (20 mm.Hg). A brown oil is obtained and is dissolved in chloroform (60 cc.). The solution is added dropwise, over the course of one hour, to a suspension of 7-aminodesacetoxycephalosporanic acid (4.28 g.) in chloroform (50 cc.) and triethylamine (5.5 cc.) kept at 5° C. The mixture is stirred for a further 45 minutes at a temperature of about 20° C. and is concentrated to dryness under reduced pressure (20 mm.Hg). The residue is taken up in water (100 cc.) and ethyl acetate (100 cc.) and the aqueous phase is brought to pH 8.5 by addition of triethylamine. The organic phase is separated by decantation. Ethyl acetate (300 cc.) is added to the aqueous phase and 4N hydrochloric acid is added until the pH is 2. The organic phase is separated, the aqueous phase is washed with ethyl acetate (100 cc.), and the organic phases are combined, dried over magnesium sulphate, treated with decolourizing charcoal and concentrated to 50 cc. under reduced pressure (20 mm.Hg). After cooling to about 0° C., the solid is filtered off and washed with ethyl acetate (2 × 20 cc.). 2-Carboxy-7-[(5,6-dihydro-1,4-dithiin-2-yl)acetamido]-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4,2,0]oct-2-ene (2.6 g.) is obtained in the form of a light beige powder.

1. temperaturethe mixture is heated
2. temperatureunder reflux until gas ceases
3. concentrationThe reaction mixture is then concentrated to dryness under reduced pressure (20 mm.Hg)
4. customA brown oil is obtained
5. customkept at 5° C
6. concentrationis concentrated to dryness under reduced pressure (20 mm.Hg)
7. additionethyl acetate (100 cc.) and the aqueous phase is brought to pH 8.5 by addition of triethylamine
8. customThe organic phase is separated by decantation
9. additionEthyl acetate (300 cc.) is added to the aqueous phase and 4N hydrochloric acid
10. additionis added until the pH is 2
11. customThe organic phase is separated
12. washthe aqueous phase is washed with ethyl acetate (100 cc.)
13. dry with materialdried over magnesium sulphate
14. additiontreated with decolourizing charcoal
15. concentrationconcentrated to 50 cc
16. temperatureAfter cooling to about 0° C.
17. filtrationthe solid is filtered off
18. washwashed with ethyl acetate (2 × 20 cc.)