Parallel synthesis of 1,3-dihydro-1,4-benzodiazepine-2-ones employing catch and release.

An efficient solid-phase method has been developed for the parallel synthesis of 1,3-dihydro-1,4-benzodiazepine-2-one derivatives. A key step in this procedure involves catching crude 2-aminobenzoimine products 4 on an amino acid Wang resin 10. Mild acidic conditions then promote a ring closure and in the same step cleavage from the resin to give pure benzodiazepine products 12. The 2-aminobenzoimines 4 can be synthesized from either 2-aminobenzonitriles 1 and Grignard reagents 2 or from iodoanilines 5 and nitriles 7 allowing a range of diversification. Further diversification can be introduced to the benzodiazepine products by N-alkylation promoted by a resin bound base and alkylating agents 13.