A practical and green protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones using oxalic acid as organocatalyst Shrikrishna Karhale 1 • Dattatray Survase 1 • Rahul Bhat 1 • Panchsheela Ubale 1 • Vasant Helavi 1 Received: 25 October 2016 / Accepted: 27 December 2016 Ó Springer Science+Business Media Dordrecht 2017 Abstract An expeditious synthesis of 2,3-dihydroquinazolin-4(1H)-ones in the pres- ence of oxalic acid as an environmentally friendly organocatalyst is reported. The salient features of the protocol are high yields, green reaction profile, shorter reaction times, and simple experimental and work-up procedure. Graphical Abstract Keywords Multi-component reactions Á Oxalic acid Á 2,3-Dihydroquinazolin- 4(1H)-ones Á Green protocol NH N H O NH N H O Oxalic Acid (20 mol%) Water:Ethanol 80 o C NH 2 O NH 2 O N H O O + + CHO R CHO R R R NH 4 OAc Res Chem Intermed DOI 10.1007/s11164-016-2855-6 & Vasant Helavi vbhelavi@gmail.com 1 Department of Chemistry, Rajaram College, Kolhapur 416004, Maharashtra, India 123