反应详情

A mixture of 3.5 g (0.012 mole) of ethyl 8-chloro-4,5-dihydro-5-methyl-4-oxopyrano[3,2-b]indole-2-carboxylate in 50 ml glacial acetic acid and 10 ml conc. hydrochloric acid was stirred at reflux for 3 hr, then cooled and added to 500 g ice - H2O. The crude product was filtered, washed with 50% aqueous ethanol, and air dried. A suspension of the product in 75 ml of chloroform was stirred for 90 min at room temperature, then filtered. After recrystallization twice from DMF-water, the final product was dried for several hours under high vacuum at 100°. The yellow flakes obtained had a mpt. of 290°-dec.

1. temperatureat reflux for 3 hr
2. temperaturecooled
3. filtrationThe crude product was filtered
4. washwashed with 50% aqueous ethanol, and air
5. customdried
6. additionA suspension of the product in 75 ml of chloroform
7. stirringwas stirred for 90 min at room temperature
8. filtrationfiltered
9. customAfter recrystallization twice from DMF-water
10. dry with materialthe final product was dried for several hours under high vacuum at 100°
11. customThe yellow flakes obtained
12. customof 290°