Isatin (1) underwent facile regioselective N-alkylation with various 2-chloro-3-chloromethylquinolines (2a-e) in the presence of KOt Bu in THF at 70°C to afford corresponding N-alkylated derivatives (3a-e). Chemical structures of products were characterized using FTIR, 1H, 13C NMR and Mass spectral studies. All the title compounds were screened for antimicrobial studies. Most of the tested compounds exhibited potent in vitro antimicrobial activity dose dependently.