Regioselective aminoethylation of 1,4-benzodiazepin-2-one under conventional heating and microwave irradiation

The regioselective aminoethylation of 1,4-benzodiazepin-2-one 1 can be carried out using classical heating or microwave irradiation as the source of energy to furnish either N-1 or N-4 aminoethylated products 2a-d and 3a-d, respectively. The regioselectivity observed has been rationalized using computational studies and has been traced to the disparity of the rate-determining steps along the N-1 product (N-1 PR) and N-4 product (N-4 PR) formation pathways.