反应详情

To a cooled suspension of 7β-formamido-3-[N,N-dimethyl-N-{(5-hydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl}ammonio]methyl-3-cephem-4-carboxylate (1.225 g) in methanol (12 ml) was added dropwise conc. hydrochloric acid (0.83 ml) at 10° C. The mixture was warmed to room temperature and stirred for 2.5 hours. The mixture was poured into ethyl acetate (300 ml) and the precipitates were collected by filtration, washed with ethyl acetate and diisopropyl ether and dried in vacuo. The powder was dissolved in cold water (10 ml) and the resulting solution was chromatographed on Diaion HP-20 (10 ml) at 5° C. and the elution was carried out with cold water. To the eluate (24 ml) was added dropwise isopropyl alcohol (12 ml) under cooling and the mixture was allowed to stand overnight in a refrigerator. The resultant crystal was collected by filtration, washed with a cold mixture of isopropyl alcohol and water (10:1) and cold isopropyl alcohol, and dried in vacuo to give 7β -amino-3-[N,N-dimethyl-N-{(5-hydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl}ammonio]methyl-3-cephem-4carboxylate dihydrochloride (440 mg).

1. filtrationthe precipitates were collected by filtration
2. washwashed with ethyl acetate and diisopropyl ether
3. customdried in vacuo
4. dissolutionThe powder was dissolved in cold water (10 ml)
5. customthe resulting solution was chromatographed on Diaion HP-20 (10 ml) at 5° C.
6. washthe elution
7. additionTo the eluate (24 ml) was added dropwise isopropyl alcohol (12 ml)
8. temperatureunder cooling
9. waitto stand overnight in a refrigerator
10. filtrationThe resultant crystal was collected by filtration
11. washwashed with a cold mixture of isopropyl alcohol and water (10:1) and cold isopropyl alcohol
12. customdried in vacuo