A study of anti-inflammatory and analgesic activity of new 2,3-disubstituted 1,2-dihydroquinazolin-4(3H)-one derivative and its transition metal complexes

Abstract

A new 2,3-disubstituted 1,2-dihydroquinazolin-4(3H)-one derivative namely 2-hydroxy-2-ethyl-(3-carboxylideneamino)-3-(2-(4-methyl-phenyl))-1, 2-dihydroquinazolin-4(3H)-one (HECMDQ) is synthesized employing a modified method in higher yield and is complexed with Co(II), Ni(II), Cu(II) and Zn(II) metal ions in order to study its coordinating behavior. All the complexes were characterized by various physicochemical (analytical, IR, NMR, Electron Paramagnetic Resonance (EPR), mass, Thermogravimetric Analysis Differential Thermogravimetric Analysis (TGA-DTA)) methods. The molar conductivity measurements in N,N-dimethylformamide (DMF) solution indicate the non-electrolytic nature of complexes. IR spectral analysis reveal that coordination takes place through the deprotonated hydroxyl group, azomethine nitrogen and carbonyl oxygen. Four coordinated geometry was assigned to all the complexes on the basis of spectral studies. The anti-inflammatory activities of compounds are moderate. Co(II) complex exhibited highest activity among all the complexes. At lower dose level activity of Ni(II) and Cu(II) complexes is more compared to that of ligand. The analgesic activity of ligand has enhanced on complexation with Co(II), Ni(II) and Zn(II) metal ions. Among the compounds studied Co(II) complex has shown highest activity and is comparable with standard used. © 2010 Pharmaceutical Society of Japan.