New derivatives and ring systems of annulated pyrrolobenzo[1,4]diazepines

(S)-11-Thioxo-2,3,11,11a-tetrahydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-5(10H)-one was subsequently reacted with amino acid esters and base to give new 6:7:5:5, 6:7:5:6, and 6:5:7:7 ring systems. The 6:7:5:5 ring system, (S)-11,12,13,13a-tetrahydro-2H-benzo[e]imidazo[2,1-c]pyrrolo[1,2-a][1,4]diazepine-3,9-dione, exhibits a considerable CH-acidity at position 2, which was exploited in Knoevenagel reactions, a Wittig reaction, enol ester formations, and methylations.