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

Participants

Reaction Steps

48.0 g (0.5 mol) of maleimide are initially introduced into the reaction vessel as a solution in 200 ml of absolute tetrahydrofuran, and 120 g (0.5 mol) of approximately 70% strength 1-(tert.-butyloxycarbonylamino)-1,3-butadiene are added dropwise as a solution in 500 ml of absolute tetrahydrofuran, the temperature being kept at 20° to 30° C. The mixture is subsequently stirred overnight at room temperature. It is then concentrated and the residue is recrystallised from ethyl acetate. 57 g of product having a melting point of 177° to 182° C. are obtained. A further 13 g of melting point 158° to 160° C. are obtained from the mother liquor.

Provenance & Evidence