Facile Synthesis of Perfluoroalkyl Substituted 1H-Benzo[b][1,4]-diazepine-2(3H)-ones via a Catalyst-Free Process

1,5-Benzodiazepin-2-one is a privileged scaffold and compounds containing such substructures exhibit a range of biological activities. Perfluoroalkyl groups can favorably affect the physical and biological properties of organic compounds. Accordingly, the development of methods to introduce perfluoroalkyl groups into 1,5-benzodiazepin-2-ones has become increasingly important. Herein, an efficient and simple route for preparation of perfluoroalkylated 1,5-benzodiazepine-2-ones is described. The reaction of methyl 3-perfluoroalkyl-2-alkynoate as the fluorinated building block with o-arylenediamine proceeds smoothly in dry toluene at 80 degrees C for 24 h without any catalyst to afford the titled compounds in good yields.