反应详情

温度

60 °C

3-Acetoxymethyl-2-carboxy-7-[(2-methylsulphinylimidazol-1-yl)-acetamido]-8-oxo-5-thia-1-aza-bicyclo[4,2,0]-oct-2-ene (8.5 g.) and sodium bicarbonate (1.62 g.) are dissolved in water (75 cc.). A solution of 2-methyl-5-thioxo-1,3,4-thiadiazoline (2.54 g.) and sodium bicarbonate (1.62 g.) in water (75 cc.) is added and the mixture is heated at 60° C. for 6 hours. After cooling, the pH is adjusted to 6 by adding hydrochloric acid (4 N) and the mixture is washed twice with ethyl acetate (a total of 200 cc.). The mixture is acidified to pH 2 by adding hydrochloric acid (4 N); a product precipitates and is filtered off and dried under reduced pressure (1 mm.Hg) to give 7.9 g. of product. Recrystallisation from methanol (25 cc.), filtration and drying under reduced pressure (0.1 mm.Hg) gives 2-carboxy-3-[(5-methyl-1,3,4-thiadiazol-2-yl)-thiomethyl]-7-[(2-methylsulphinyl-imidazol-1-yl)-acetamido]-8-oxo-5-thia-1-aza-bicyclo[4,2,0]oct-2-ene (2.7 g.), m.p. 227° C. (with decomposition), [α]D20 = -35° ± 1° (c= 1, dimethylformamide).

1. temperatureAfter cooling
2. washthe mixture is washed twice with ethyl acetate (a total of 200 cc
3. additionby adding hydrochloric acid (4 N)
4. customa product precipitates
5. filtrationis filtered off
6. customdried under reduced pressure (1 mm.Hg)
7. customto give 7.9 g
8. customRecrystallisation
9. filtrationfrom methanol (25 cc.), filtration
10. customdrying under reduced pressure (0.1 mm.Hg)