反应详情

0.520 g of the product of Step F of Example 1 and 0.390 g of 4-amino benzoic acid were introduced into 6 ml of 2N hydrochloric acid and the solution was refluxed for 63 hours. The precipitate was filtered off, washed with water and taken up in 10 ml of 2N sodium hydroxide in 40 ml of water, then washed with ethyl acetate. The aqueous phase was taken up in acetic acid and the precipitate was filtered, washed with water, separated out and taken up in ether. After drying, 220 mg of the expected product melting at 276° C. were obtained.

1. temperaturethe solution was refluxed for 63 hours
2. filtrationThe precipitate was filtered off
3. washwashed with water
4. washwashed with ethyl acetate
5. filtrationthe precipitate was filtered
6. washwashed with water
7. customseparated out
8. customAfter drying