ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2015.19132 INTRODUCTION Quinazoline and its derivatives are versatile nitrogen containing heterocyclic compounds, demonstrating a broad spectrum of biological and pharmacological activities in animal as well as in human beings 1,2 . The chemistry and pharmacology of quinazolines have been of great interest to medicinal chemists. Wedding in 1885 synthesized the first quinazolines and later on, extensive work on this nucleus was done for the amelioration of human suffering from various diseases and many drugs incorporating this nucleus were developed. The designing and devolvement of selective non-nucleoside inhibitors of virus polymerases is an emerging area of research activity. Interest in discovering non-nucleoside inhibitor of virus polymerases increase after the pronounced antiviral activity of 2-(α-hydroxybenzyl)benzimidazole (HBB) and methisazone which are truly the selective inhibitors of RNA polymerase 3,4 subsequently other synthetic compounds were developed and assayed for their antiviral activity. Amongst various synthetic compounds quinazolines have been demons- trated to be potential candidate molecules against several strains of virus since such compound exhibit varying degree of virus inhibition properties against semliki forest disease virus (SFV) 5 , Ranikhet disease virus (RDV) 6 , Encephalomyo- carditis virus (EMCV) 7 , Japanese encephalitis virus (JEV) 8 and Herpes simplex virus type-I (HSV-I) 9 , Interest in quina- zolones chemistry has increased many folds because of their Synthesis and Antiviral Activities of Some 2,3-Disubstituted Quinazoline Derivatives V.D. GUPTA * , JOGINDER SINGH, MAYANK KINGER, AVNISH KUMAR ARORA and VIVEK SHEEL JASWAL Department of Chemistry, Maharishi Markandeshwar University, Mullana, Ambala-133 207, India *Corresponding author: Fax: +91 1731 274375; Tel: +91 1731 304100; E-mail: vishnugupta442@gmail.com Received: 26 February 2015; Accepted: 17 April 2015; Published online: 29 August 2015; AJC-17475 In the search of new leads towards potent antiviral agents 2,3-disubstituted quinazoline derivatives were synthesized and tested for their antiviral activity. Anthranilic acid (1) on treatment with an aromatic acid chloride in pyridine gives 2-aryl-4-oxo-3H-benzoxazines (2) which in turn reacts with p-amino benzoic acid (PABA) to afford 2-aryl-3-p-carboxylatophenyl-4-oxo-3H-quinazolines (3). The compound 3 further reacts with amido alcohols in the presence of conc. H2SO4 resulting 3-[benzoic acid-(3-phthalimidomethyl/3-ethyl-3H-2-phenyl- 4-oxo-quinazolinyl/1-ethyl-7-hydroxy-4-methyl-2-oxo-quinolinyl)]-2-aryl-3H-quinazoline-4-ones (4). The resulting compounds 4a-f have been evaluated for their in vitro and in vivo antiviral activity against JEV and HSV type-I. The synthesized compounds were characterized through their physical and chemical analysis. The obtained results can be used as the key step for the building of novel chemical entities with interesting antiviral activity compare with the standard drugs. Keywords: Antiviral activities, 2,3-Disubstituted quinazoline derivatives. Asian Journal of Chemistry; Vol. 27, No. 12 (2015), 4379-4382 association with varying degree of antiviral activity against animal and plant viruses 10-12 . These valid observations led the authors to undertake the synthesis of 2,3-disubstituted quinazolones in order to study their antiviral activity against both, RNA and DNA viruses. EXPERIMENTAL Melting points of the compounds were determined in open glass capillaries in the Toshniwal melting points apparatus and recorded values are uncorrected. IR spectra were recorded in KBr on Perkin-Elmer 157 spectrophotometer in region νmax 4000-400 cm -1 and 1 H NMR and 13 C NMR spectra were recorded on Brooker DRX 200 MHz spectrophotometer using CDCl3 as solvent (TMS as internal standard with chemical shift in δ, ppm). Mass spectra were recorded on Hitachi-Elmer model RMV-7 spectrometer at 70 eV. Synthesis of 2-aryl-4-oxo-3,1-benzoxazines (2): The titled compound was prepared according to the method described in the literature 13 . Anthranilic acid (0.1 mol) was dissolved in anhydrous pyridine (50 mL) by stirring slowly at room temperature. The solution was cooled to 0 °C and an aromatic acid chloride (0.2 mol) was added drop wise slowly with constant stirring. After complete addition, the reaction mixture was further stirred for 0.5 h at room temperature and kept for 1 h. The dense mass, thus obtained, was diluted with deionized water (50 mL) and treated with 5 % NaHCO3