反应详情

3,4-Dihydro-4-methylcyclopent[b]indol-1(2H)-one oxime (1.53 g), polyphosphric acid (450 g) and dioxan (15 ml) were heated at 100°-120° for 2.2 h under nitrogen. The reaction mixture was cooled, and treated with 2N sodium carbonate solution (1 l). The suspension was extracted with ethyl acetate (4×400 ml) and the combined extracts were dried. Evaporation gave a solid (1.43 g) which was recrystallised from ethyl acetate/cyclohexane. This solid was purified by FCC, eluting with System A (200:10:1) to give a solid (1.26 g) which was recrystallised from ethanol to provide the title compound (960 mg), m.p. 234°-238°.

1. temperatureThe reaction mixture was cooled
2. extractionThe suspension was extracted with ethyl acetate (4×400 ml)
3. customthe combined extracts were dried
4. customEvaporation