A General Synthetic Route to Isomeric Pyrrolo­[1,2‑x]­[1,4]­diazepinones

A simple one-pot method for the synthesis of isomeric pyrrolo­[1,2-x]­[1,4]­diazepinones in reasonable yields was developed. The method is based on the condensation of readily available N-Boc amino acids with biomass-derived furans containing aminoalkyl groups followed by deprotection, furan ring opening, and Paal–Knorr cyclization. Using this approach, we synthesized pyrrolo­[1,2-a]­[1,4]­diazepin-3­(2H)-ones from furfurylamines and β-amino acids and pyrrolo­[1,2-d]­[1,4]­diazepin-4­(5H)-ones from 2-(2-furyl)­ethylamines and α-amino acids. The cytotoxicity of the synthesized pyrrolodiazepinones was studied.