11-(Tetrahydro-3 and 4-pyridinyl)dibenzo[b,e][1,4]diazepines undergo novel rearrangements on treatment with concentrated HBr

11-(1,2,5,6-Tetrahydro-1-methyl-3-pyridinyl)-5-methyl-5H-dibenzo[b,e][1,4]diazepine on heating in conc. HBr afforded trans-5-(2-aminophenyl)-1,3,4,4a,5,10a-hexahydro-2-methylbenzo[b][1,6]naphthyridin-10(2H)-one in one step. The isomer 11-(1,2,5,6-tetrahydro-1-methyl-4-pyridinyl)-5-methyl-5H-dibenzo[b,e][1,4]diazepine underwent a novel rearrangement resulting in the pentacycle, 4-amino-5,13-diaza-13-methyl-bicyclo[3.3.1]nonan[6,7,8-k,l]acridine.