ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2015.18362 INTRODUCTION The ideology of green chemistry calls for the development of new chemical reactivity's and reaction conditions that can provide benefits for the chemical synthesis 1 . Employment of heterogeneous catalysts in organic synthesis is one of these greener methods and amongst various heterogeneous catalysts, the use of resin as a catalyst has received paramount attention over its companion reagents owing to its stability in water and air 2-4 . In addition, the growing concern for the influence of the chemical reagents on the environment as well as on human body, recovery and reusability of the chemical reagents have attracted the attention of synthetic organic chemists. Notably, pharmaceutical industry has given more priority toward recovery and reuse of chemical reagents to reduce the cost of a product as well as the environmental burden. Indion Ina 225H resin is a macro reticular, srongly acidic, unifunctional, premium grade inexpensive cation exchange resin containing sulfonic acid groups. It is an insoluble copolymer with styrene divinylbenzene cross-linked matrix and appears as golden yellow beads. The resin is extremely robust having excellent physical and chemical characteristics 5 . Utility of this resin as a catalyst for organic reactions 6 has been scarcely investigated and its unique nature prompted us to synthesize heterocyclic scaffolds using this resin. 2,3-Dihydroquinazoline-4(1H)-one moiety is an impor- tant pharmacophore and privileged structure in medicinal chemistry 7-10 . Its potential biological activity and wide natural occurrence has fascinated many researchers to develop a plethora of elegant synthetic methods. Of these, a simple and direct approach for synthesis of 2,3-dihydroquinazoline-4(1H)-ones Green Protocol for the Synthesis of 2-Aryl-2,3-dihydroquinazoline-4(1H)-ones Using Indion Ina 225H Resin K. SATISH REDDY, T. PARTHASARATHY, K. SANTOSH KUMAR and APURI SATYENDER * Department of Chemistry, University College of Science, Osmania University, Hyderabad-500 004, India *Corresponding author: E-mail: apuri.satyender@yahoo.in Received: 21 June 2014; Accepted: 16 September 2014; Published online: 17 March 2015; AJC-16997 Synthesis of 2-aryl-2,3-dihydroquinazoline-4(1H)-ones is described by using new and novel heterogeneous catalyst, Indion Ina 225H resin. Anthranilamide was reacted with a series of aromatic aldehydes in presence of resin to afford various 2-aryl substituted 2,3- dihydroquinazoline-4(1H)-ones. The resin employed in these reactions can be recovered and reused. Keywords: Green chemistry, Indion Ina 225H resin, 2,3-dihydroquinazolin-4(1H)-ones, heterogeneous catalyst. involves condensation of anthranilamide and carbonyl com- pounds. To accomplish this transformation, an assortment of catalysts such as ionic liquids 11 , cellulose-SO 3 H 12 , NH 4 Cl 13 , Amberlyst 14 , TiCl 4 /Zn 15 , CuCl 2 16 , trifluoroacetic acid 17 , and chiral phosphoric acids 18 , etc. are employed. However, pitfalls asso- ciated with these methods demands for development of a green protocol involving low cost, easily available, easy to handle and efficient catalysts. EXPERIMENTAL Thin-layer chromatography (TLC) was performed on Merck AL silica gel 60 F254 plates and visualized under UV light. The column chromatography was performed using Merck silica gel (60-120 mesh). The 1 H NMR spectra were recorded in DMSO-d6 at 400 MHz on a VARIAN spectrometer. All the chemical shift values are reported in δ units using TMS as internal standard. The Mass spectra were recorded using PE-SCIEX-API-3000 system. General procedure for synthesis of 2,3-dihydroquina- zolin-4(1H)-ones (4a-o): Ina 225H resin (30 % w/w with respect to 2) was added to a solution of anthranilamide (2) (1 mmol) and aldehyde (3a-o, 1 mmol) in methanol (5 mL). The mixture was stirred at room temperature for an appropriate time (Table-1). After complete conversion (confirmed by TLC), the catalyst was filtered and washed with methanol. Filtrate was concentrated and purified by silica-gel column chromato- graphy to afford compounds 4a-o. 2-(Naphthalen-2-yl)-2,3-dihydroquinazolin-4(1H)-one (4a): 1 H NMR (400 MHz, DMSO-d6) δ: 8.52 (d, J = 16 Hz, 1H) 8.32 (s, 1H), 8.05-7.90 (m, 2H), 7.77-7.62 (m, 2H), 7.50- Asian Journal of Chemistry; Vol. 27, No. 6 (2015), 2222-2224