1,3-Cyclohexadiene → 3a-(3,4-dichlorophenyl)-2-ethyl-3a,4,7,7a-tetrahydro-4,7-ethano-1H-isoindol-1,3(2H)-dione

Participants

Reaction Steps

A solution of 7.5 g of the above maleimide, 2.25 g of 1,3-cyclohexadiene, and 10 mg of methylene blue in 25 ml of dichloromethane was heated at reflux for 5 hours, then an additional one ml of the diene was added and the solution was heated for 24 hours. The cooled reaction mixture was subjected to high pressure liquid chromatography on a silica gel column eluting with hexane:ethyl acetate (4:1) and gave 5.58 g of 3a-(3,4-dichlorophenyl)-2-ethyl-3a,4,7,7a-tetrahydro-4,7-ethano-1H-isoindol-1,3(2H)-dione as a white solid, mp 122°-126° C.

Provenance & Evidence