Synthesis, physicochemical characterization and analgesic evaluation of some new thieno [2,3-D] Pyrimidin 4(3H) one derivatives

A POCl3 catalyzed, efficient, one-step and solvent-free synthesis of novel thieno [2,3-d] pyrimidin-4(3H)-one derivatives from 2-amino-4,5-substitutedthiophene-3-carbonitrile has been developed using various aliphatic acid under both conventional heating and microwave irradiation techniques. The formation of compounds was confirmed via elemental analysis and spectroscopic techniques like FTIR, 1HNMR and mass spectroscopy. All synthesized compounds have been screened for their analgesic activity by using Eddy´s hot plate method. The synthesized compounds 2d, 2k and 2h showed good analgesic activity and compounds 2a, 2b, 2g and 2i showed moderate whereas remaining compounds possessed less analgesic activity compared with standard, Tramadol. Keywords: POCl3, Thieno[2,3-d]pyrimidin-4 (3H)-one, Analgesic activity, Eddy´s hot plate.