Synthesis and Antiproliferative Evaluation of Hybrids of Indolin-2-one and Quinazoline-4(3H)-one Linked via Imine Bond

A novel series of hybrids of indolin-2-one and quinazolin-4(3H)-one linked via an imine bond were synthesized and tested for their inhibitory activity against the proliferation of a panel of five human cancer cell lines. We found that compound 5c bearing 5-bromo substituent at the indolin-2-one ring exhibited weak cytotoxic activity with percentages of inhibition ranging from 27% to 49% at 20 μM, while its counterpart 7c having 4-methoxybenzyl group at the N1-position of indolin-2-one ring was more active with percentages of inhibition in range of 32-63%. These results indicate that the presence of a bromo substituent at the 5-position and a 4-methoxybenzyl group at the N1-position of indolin-2-one ring is important for the cytotoxic activity.