m-Chloroperbenzoic acid → HCID 67883980, compound

Participants

Reaction Steps

A solution of 3.04 g (15 mmol) of m-chloroperbenzoic acid in 30 ml of dichloromethane is added dropwise over a period of 45 minutes, at -15° with stirring, to a solution of 2.3 g (10 mmol) of (9bR*,13aR*)-2-oxo-1,4,5,10,11,12,13,13a-octahydro-2H-pyrrolo[2',1':3,4]-pyrazino[2,1-i]indole in 30 ml of dichloromethane. The reaction mixture is then stirred for 4 hours at -15°, then diluted with 100 ml of dichloromethane and washed in succession, ice-cold, with sodium hydrogen sulfite solution (5%) and sodium hydrogen carbonate solution (5%). The organic phase is separated off, dried over sodium sulfate and concentrated by evaporation in vacuo. In this manner a crude product is obtained, which is chromatographed on 120 g of silica gel (0.040-0.063 mm) using trichloromethane as eluant. The desired (9bR*,13aR*)-2,7-dioxo-1,4,5,7,8,10,11,12,13,13a-decahydro-2H-pyrrolo[2',1':3,4]pyrazino[2,1-i]indole is obtained from the appropriate fractions in the form of a foam, which is crystallised from dichloromethane/diethyl ether and then melts at 105° to 125°. Also obtained is the (9aR*,9bR*,13aR*) isomer of 2,7-dioxo-1,4,5,7,9a,10,11,12,13,13a-decahydro-2H-pyrrolo[2',1':3,4]pyrazino[2,1-i]indole in the form of an oil, which is crystallised from dichloromethane/diethyl ether and then melts at 159° to 162°.

Provenance & Evidence