ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2016.19676 INTRODUCTION Quinazoline skeletons showed potent biological activities such as anticancer, antitumor, antibiotic, antidefibrillator, antipyretic, analgesic, antihypertonic, antimalarial and diuretic activities depending up on the biological activities [1-9]. They were considered as important group in heterocyclic molecules. An accountable work was carried out to develop simple and direct approaches for the synthesis of dihydroquinazolin- 4-ones skeleton for the past few years. These methods comprises of condensation of anthranilamide with substituted carbonyl compounds in the presence of various catalysts such as cyanuric trichloride [10], Ce(NH 4 ) 2 (NO 3 ) 6 [11], citric acid- Al 2 O 3 [12], H 3 BO 3 [13], gallium(III) triflate [14], Sulfamic acid [15], Bu 4 N + Br (–) [16], zinc(II) chloride [17], toluene-4- sulfonic acid [18], ruthenium [19], 2,2,2-trifloroethanol [20], TiCl 4 -Zn [21] and ZrCl 4 [22]. But many of the established methods are not feasible in all respects such as cost of the reagents, attaining good yields of the products, purification of the products and in some of the methods preparation of reagent is also complicate. So, in order to extend this study towards development of simple and viable method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones an attempt was carried out with thionyl chloride as catalyst for ethanol mediated condensation of anthranilamide and aldehydes. Synthesis, Anticancer and Antioxidant Evaluation of Some New 2-Aryl and 2-Pyrazole-2,3-dihydroquinazolin-4(1H)-ones RAMESH NAVUDU 1 , GANGADHARA RAO MANNEM 1 , TIRUMALA MARGANI 1 , UMA MAHESWARA RAO VANGA 2 and HARI BABU BOLLIKOLLA 1,* 1 Department of Chemistry, Acharya Nagarjuna University, Nagarjuna Nagar-522 510, India 2 Department of Botany & Microbiology, Acharya Nagarjuna University, Nagarjuna Nagar-522 510, India *Corresponding author: E-mail: dr.b.haribabu@gmail.com Received: 16 October 2015; Accepted: 21 January 2016; Published online: 29 February 2016; AJC-17800 A new and direct synthetic method was developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by condensing 2-aminobenzamide and aldehydes in ethanol using thionyl chloride as a catalyst at room temperature. The simple reaction conditions, small timing, easy work up and very good yields are the greatest advantages of this methodology. By utilizing the approach six novel derivatives of 2-aryl-2,3- dihydroquinazolin-4(1H)-ones (3a-3f) were synthesized. All the compounds were tested for their anticancer activity on A549 cell line and antioxidant activity by using DPPH method. Compounds 3c (74.22 %) and 3e (73.45 %) showed better anticancer activity towards the A549 cell line. Keywords: SOCl2, Anthranilamide, Novel pyrazole derivatives, Anticancer; Antioxidant activity. Asian Journal of Chemistry; Vol. 28, No. 6 (2016), 1321-1324 EXPERIMENTAL All the chemicals used were of Merck. Reagent grade solvents (E. Merck) were used as such. All the melting points were obtained from Remi melting point apparatus. All reactions were monitored by TLC and all yields refer to isolated products. Proton NMR spectra were recorded in DMSO-d 6 on Bruker 400 MHz and 13 C NMR spectra were on Bruker 100 MHz, Mass studies were carried out on LC-MS system equipped with Agilent 1100 series, LC/MSD detector and 1100 series Agilent HPLC pump. Preparation of 2,3-dihydroquinazolin-4(1H)-ones: To a mixture of anthranilamide (1 mmol) and aldehyde (1 mmol) in ethanol (10 mL), catalytic amount of thionyl chloride was added to reaction mixture at 0-5 °C, the mixture was stirred at room temperature for about 30-35 min. After completion of the reaction monitored by TLC, the ethanol was distilled off from the reaction mass, the solid mass was poured into cold water (25 mL) filtered off and the product then washed with cold ethanol for further purification. Finally, the dried compounds were characterized by their spectral data. 3-Methoxy-4-(4-oxo-1,2,3,4-tetrahydroquinazolin-2- yl)benzonitrile (3a): This compound was obtained as a white solid; m.p. 238-240 °C; 1 H NMR (400 MHz, DMSO-d 6 ): δ 3.89 (s, 3H), 6.01 (s, 1H), 6.68 (t, J = 7.2 Hz, 1H), 6.76 (d, J = 7.8 Hz, 1H), 6.91 (s, 1H), 7.24 (t, J = 7.12 Hz, 1H), 7.43 (d,