Quinoline-3-carboxylates as potential antibacterial agents V. Krishnakumar • Fazlur-Rahman Nawaz Khan • Badal Kumar Mandal • Sukanya Mitta • Ramu Dhasamandha • Vindhya Nanu Govindan Received: 9 December 2011 / Accepted: 6 February 2012 / Published online: 29 February 2012 Ó Springer Science+Business Media B.V. 2012 Abstract The ethyl-2-chloroquinoline-3-carboxylates, 4, were achieved from o-am- inobenzophenones in two steps. i.e. initially, the ethyl-2-oxoquinoline-3-carboxylates, 3, were obtained by base-catalyzed Friedlander condensations of o-aminobenzophe- nones, 1, and diethylmalonate, 2. The 2-chloroquinoline-3-carboxylates, 4, were then obtained by the reaction with POCl 3 in good yields. The chemical structures were confirmed by FTIR, mass and 1 H-NMR spectroscopic techniques. All the synthesized compounds were tested for their in vitro antibacterial activity against Bacillus subtilis and Vibrio cholera and found to possess moderate activity. Keywords Quinolines Á Friedlander synthesis Á Antibacterial activity Introduction Quinoline heterocycles occur widely among medicinally important natural products. Several natural products possessing quinoline moiety exhibit interesting biological and pharmacological properties, such as antimalarial [1, 2], antibacterial [3], anti- asthmatic, antihypertensive, anti-inflammatory [4], immunosuppressive activity [5], antileishmanial activity [6], and anticancer [7] properties. In addition, quinolines have been employed in the study of bioorganic and bioorganometallic processes [8]. These properties turn quinolines into very interesting targets for organic chemists, and several strategies for their synthesis have been developed including Skraup [9], V. Krishnakumar Á F.-R. N. Khan (&) Á S. Mitta Á R. Dhasamandha Á V. N. Govindan Organic and Medicinal Chemistry Research Laboratory, Organic Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India e-mail: nawaz_f@yahoo.co.in V. Krishnakumar Á B. K. Mandal Environmental and Analytical Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India 123 Res Chem Intermed (2012) 38:1819–1826 DOI 10.1007/s11164-012-0505-1