J. Indian Chcm. Soc., Vol. 88, June 2011, pp. 835-839 Synthesis and antiviral activity of 2-aryl-3-(substituted-benzalamino)-4(3H)- quinazolinones Shradha Pandey*, Pravin K. Singh, I. R. Siddiqui and Jagdamba Singh Environmentally Benign Laboratory, Department of Chemistry, University of Allahabad, Allahabad-211 002, Uttar Pradesh, India E-mail : shradha.06@gmail.com Fax : 91-532-2462240 Manuscnpt received 06 April 2010, accepted 16 November 2011 Abstract : A series of new heterocyclic compounds 2-aryl-3-(suhstituted-henzalamino)-4(3/1)-quinawlinone have been thesized by the treatment of 3-amino-2-aryi-4(3H)-lluinazolinone "ith a substituted benzaldehyde in ethanol. All the n- thesized com(lounds were characterized by elemental anal:tsis, IR, 1 11 Nl\fR, 13 c NMR and mass spectra. The sized compounds were screened for their antiviral activity. The were found to moderate to good antiviral activity. Keywords : 4(311)-Quinazolinone, Schiff synthesis, antiviral activity. Introduction Synthesis of quinazolinone heterocycles is an attrac- tive field for synthetic chemists due to their diverse range of pharmacological activities 1 · 2 . 4(3H)-Quinazolinones occupy an important position in medicinal and pesticidal chemistry, presenting a wide range of bioactivities. As medicines, many of them display antifungal 3 , antimicro- bial4, anti-HIV 5 , antitubercular 6 , anticancer 7 , anti-inflam- matory8, anticonvulsant 9 , antidepressant 10 , hypolipi- demic11, antiulcer 12 , analgesic 13 or immunotropic activi- ties 14 and are also known to act as thymidyalate syn- thase IS, poly(ADP-ribose)polymerase (PARP) 16 and pro- tein tyrosine kinase 17 inhibitors. As pesticides, they are used as insecticides 18 , fungicides 19 and antiviral agents20 such as TMV, CMV inhibitors. In light of the growing number of applications in recent years there has been an enormous increase in the interest among biologists and chemists in their synthesis and bioactivity of quinazolinone derivatives. In the present work we have designed and synthesized a series of 2-aryl-3-(substituted-benzalamino)-4(3H)- quinazolinone derivatives 3(a-h) and investigated their antiviral bioactivities. The route is shown in Scheme I. The of these compounds were firmly established by well defined IR, 'H NMR, 13 C NMR, Mass spectra and elemental analysis. Preliminary bioas- say tests showed that some compounds displayed in vivn antiviral activity against TMV at 500 ).tg/ml. The subs- tituents and yields of the title compounds 3(a-h) is given in Table I. Table 1. Subslltuents and of title 3(a-h) Compd. R1 R 2 R Yields(%) 3a H Ph 4-CI 72 3b H Ph 4·N0 2 68 3c H Ph 4-0CH 3 71 3d II Ph 4-CF 3 75 3c 6-Br Ph 4-CI 73 3f 6-Br Ph 4-N0 2 71 3g 6-Br Ph 4-0CII 3 69 3h 6-Br Ph 4-CF 3 79 Results and discussion The title 2-aryl--3-(substituted-benzalamino)-4(3H)- quinazolinone compounds J(a-h) were synthesized by the reaction of 3-amino-2-aryi-4(3H)-quinazolinone with sub- stituted benzaldehyde in ethanol in presence of few drops of acetic acid. The structures of the compounds were characterized by elemental analysis, IR, 1 H NMR and I3c NMR and mass spectra. Here we have synthesized 8 compounds and these compounds have been screened for their antiviral activity. The compounds were found to possess moderate to good antiviral activity. 835