1,1'-Carbonyldiimidazole → 3,4,4a,5-tetrahydro-5-methylpyrimido-[1,6-a]indol-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

To a solution of crude 2-(2,3-dihydro-3-methylindol-2-yl)ethylamine (1.75 g) in tetrahydrofuran 12 ml) at room temperature was added in small portions 1,1'-carbonyldiimidazole (1.1 g). After being stirred for hours, the reaction mixture was evaporated in vacuo. The oil obtained was dissolved in toluene (25 ml) and the solution was heated at 110° C. for 1.5 hours. After evaporation of the solvent, the residue was purified by silica gel column chromatography (1% methanol-chloroform) to give crystals. Recrystallization from chloroform-ethyl acetate-hexane gave 3,4,4a,5-tetrahydro-5-methylpyrimido-[1,6-a]indol-1(2H)-one (0.65 g).

Provenance & Evidence