反应详情

A mixture of 1.0 g (0.0033 mole) of ethyl 4,5-dihydro-4-oxo-5-phenylpyrano[3,2-b]indole-2-carboxylate in 10 ml glacial acetic acid and 2.0 ml conc. hydrochloric acid was stirred at reflux for 41/2 hr, then cooled and added to 75 g ice--H2O. The solid was filtered, washed with cold water, then added to a mixture of 35 ml 5% aqueous sodium carbonate and 250 ml water. After filtering by gravity, the aqueous solution was washed three times with 75 ml chloroform, cooled in ice, and acidified with 4.0 N hydrochloric acid. The orange precipitate was filtered, digested 15 min on the steam bath with 25 ml water and re-filtered warm. Recrystallization from DMF-water yielded an off-white solid of mpt. >290°.

1. temperatureat reflux for 41/2 hr
2. temperaturecooled
3. filtrationThe solid was filtered
4. washwashed with cold water
5. additionadded to a mixture of 35 ml 5% aqueous sodium carbonate and 250 ml water
6. filtrationAfter filtering by gravity
7. washthe aqueous solution was washed three times with 75 ml chloroform
8. temperaturecooled in ice
9. filtrationThe orange precipitate was filtered
10. filtrationre-filtered
11. temperaturewarm
12. customRecrystallization from DMF-water
13. customyielded an off-white solid of mpt
14. custom>290°