Highly efficient one-pot, three-component synthesis of 1,5-benzodiazepine derivatives

A general, mild and efficient protocol for the synthesis of ethyl 4-methyl-2-(thiophen)-2,5-dihydro-1,5-benzodiazepine-3-carboxylate is achieved for first time using H3PMo12O40 in ethanol at 0 °C by a one-pot, three-component condensation of various thiophene aldehydes, substituted o-phenylenediamines and ethyl acetoacetate. Compared with the conventional synthesis method, this procedure has the advantages of convenient operation, excellent yields, and environmentally benign. A plausible formation mechanism has been proposed. The structure of the products is characterized by 1H NMR, IR, MS and elemental analysis.

Graphical abstractA general, mild and efficient protocol for the synthesis of ethyl 4-methyl-2-(thiophen)-2,5-dihydro-1,5-benzodiazepine-3-carboxylate was achieved for first time using H3PMo12O40 in ethanol at 0 °C by a one-pot, three-component condensation of various thiophene aldehydes, substituted o-phenylenediamines and ethyl acetoacetate and is reported. This procedure has the advantages of convenient operation, excellent yields, and environmentally benign.Figure optionsDownload full-size imageDownload as PowerPoint slide