反应详情

19.4 g (44.17 mmoles) of the compound from Example I is stirred for 10 hours at 180° C. in 216 ml of formamide. After cooling, 500 ml of water is added and extracted 4 times with 300-ml portions of CH2Cl2. The combined organic phases are dried over MgSO4, the solvent is evaporated under vacuum, and the residue is stirred in a mixture of 100 ml of diethyl ether and 50 ml of petroleum ether. The product (17.8 g) is filtered off by suction and recrystallized from 250 ml of absolute ethanol.

1. temperatureAfter cooling
2. extractionextracted 4 times with 300-ml portions of CH2Cl2
3. dry with materialThe combined organic phases are dried over MgSO4
4. customthe solvent is evaporated under vacuum
5. filtrationThe product (17.8 g) is filtered off by suction
6. customrecrystallized from 250 ml of absolute ethanol