Synthesis of novel tricyclic derivatives of 7-azabenzonorbornene system

The reaction of 6-methyl-5,6-dihydroisoindolo[2,1-a]quinazolin-5-one with maleinimides in the ratio 1:2 was investigated. The products of the reaction were tricyclic derivatives of 7-azabenzonorbornene system 2-methyl-20-R-11-(1-R-2,5-dioxotetrahydro-1H-3-pyrrolyl)-2,10,20-triazahexacyclo[9.6.5.01,10.04,9.012,17.018,22]docosa-4(9),5,7,12,14,16-hexaene-3,19,21-trione. Their structure was established by the X-ray analysis, and a probable mechanism of the reaction is considered.