反应详情

1.66 g of the product of Example 1 were introduced into 30 ml of methanol, 10 ml of chloroform and 10 ml of 2N hydrochloric acid, and the mixture was refluxed for 50 minutes. 100 ml of water were added and extraction was carried out 3 times with ethyl acetate. The organic phase was washed with salt water, dried and purified on silica with methylene chloride-acetone: 85-15 as eluant. The resultant product was dissolved in 100 ml of isopropanol at about 70° C. and filtration was carried out, followed by concentrating, ice-cooling for one hour, separating and drying to obtain 1,425 g of the expected product (white crystals) melting at 192°-193° C.

1. temperaturethe mixture was refluxed for 50 minutes
2. extractionextraction
3. washThe organic phase was washed with salt water
4. customdried
5. custompurified on silica with methylene chloride-acetone
6. dissolutionThe resultant product was dissolved in 100 ml of isopropanol at about 70° C.
7. filtrationfiltration
8. concentrationby concentrating
9. temperatureice-cooling for one hour
10. customseparating
11. customdrying