Maleimide → 4-(Tert.-butyloxycarbonylamino)-1,3-dioxo-1,3,3a,4,7,7a-hexahydroisoindole

Participants

Reaction Steps

48.8 g (0.5 mol) of maleimide dissolved in 200 ml of absolute tetrahydrofuran are initially introduced, and 120 g (0.5 mol) of approximately 70% 1-(tert.-butyloxycarbonylamino)-1,3-butadiene in the form of a solution in 500 ml of absolute tetrahydrofuran are added dropwise, the temperature being maintained at 20° to 30° C. Stirring is continued overnight at room temperature. The mixture is then concentrated and recrystallized from ethyl acetate. This gives 57 g of product with a melting point of 177° to 182° C. A further 13 g with a melting point of 158° to 160°C. are obtained from the mother liquor.

Provenance & Evidence