A novel series of compounds combining indolin-2-one and quinazolin-4（3H）-one moiety via a carbon-carbon double bond were synthesized by aldol-condensation of 2-methylquinazolin-4（3H）-one-6-carbaldehyde with various indolin-2-ones. The synthesized compounds were evaluated for their cytotoxic activity against five human cancer cell lines, namely, A549, MCF-7, HeLa, HT-29 and HCT-116. We found that compound 5e with two bromine atoms at the 5- and 7-positions of the indolin-2-one ring was most potent, which inhibited proliferation of five cancer cell lines in the range of 32.0%-62.3% at a concentration of 50 p,M. Our results further indicate that the connection of 5,7-dibromoindolin-2-one and 2-methylquinazolin- 4（3H）-one moiety with a carbon-carbon double bond is essential for compound 5e to exert cytotoxicity.
