反应详情

温度

60 °C

3-Acetoxymethyl-2-carboxy-8-oxo-7-[(1,3-dithiol-2-on-4-yl)-acetamido]-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (7 g.) is dissolved in distilled water (100 cc.) and sodium bicarbonate (1.46 g.). A solution of 5-ethyl-2-thioxo-1,3,4-thiadiazoline (2.63 g.) in distilled water (60 cc.) and sodium bicarbonate (1.46 g.) is added and the resulting solution is heated to 60° C. for 6 hours. After cooling, it is acidified to pH 5.5 by adding 4 N hydrochloric acid and is then extracted twice with ethyl acetate (100 cc.). The organic extracts are discarded. The acidification is continued in the presence of ethyl acetate (300 cc.) until the pH is 2. After decanting the organic phase, the aqueous phase is extracted twice with ethyl acetate (a total of 200 cc.). The combined organic extracts are washed twice with water (200 cc.), dried over magnesium sulphate, treated with decolourising charcoal and then filtered and concentrated to dryness under reduced pressure (20 mm.Hg). The residue obtained is recrystallised from methanol (100 cc.) to give 2-carboxy-3-[(5-ethyl-1,3,4-thiadiazol-2-yl)-thiomethyl]-8-oxo-7-[(1,3-dithiol-2-on-4-yl)-acetamido]-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene (2 g.) m.p. 155° C.

1. temperatureAfter cooling
2. extractionis then extracted twice with ethyl acetate (100 cc.)
3. customAfter decanting the organic phase
4. extractionthe aqueous phase is extracted twice with ethyl acetate (a total of 200 cc
5. washThe combined organic extracts are washed twice with water (200 cc.)
6. dry with materialdried over magnesium sulphate
7. additiontreated with decolourising charcoal
8. filtrationfiltered
9. concentrationconcentrated to dryness under reduced pressure (20 mm.Hg)
10. customThe residue obtained
11. customis recrystallised from methanol (100 cc.)