反应详情

125 g of cephradine dimethylformamide solvate (as for example produced in step a) above) were suspended in water/conc. HCl (300/12.5) at 5° to 10° C. with stirring. The pH was adjusted to 1.6 to 2.0 by addition of hydrochloric acid in order to obtain a complete solution. The solution was filtered and the residue washed with 60 ml of water. The combined filtrate was warmed to 35° to 40° C. The pH was adjusted to 2.4 to 2.8 with triethylamine whereupon precipitation started. The stirring was maintained for several minutes. The pH was then adjusted to 4.7 to 5.1 with triethylamine and the suspension was cooled to about 25° and filtered. The residue was washed with 270 g of acetone (80% v/v) to obtain the heading compound, m.p. 190° to 200° C. (decomp.).

1. customto obtain a complete solution
2. filtrationThe solution was filtered
3. washthe residue washed with 60 ml of water
4. temperatureThe combined filtrate was warmed to 35° to 40° C
5. customThe pH was adjusted to 2.4 to 2.8 with triethylamine whereupon precipitation
6. temperatureThe stirring was maintained for several minutes
7. temperaturethe suspension was cooled to about 25°
8. filtrationfiltered
9. washThe residue was washed with 270 g of acetone (80% v/v)
10. customto obtain the heading compound, m.p. 190° to 200° C. (decomp.)