Microwave Assisted Synthesis and 3D QSAR Analysis of Analgesic Oxadiazoles

In present work we report design, synthesis and evaluation of the analgesic activity of new 2, 5-disubstituted1, 3, 4-oxadiazoles. An ecofriendly method for the conversion of substituted benzoic acid hydrazides to 2, 5-disubstituted1, 3, 4-oxadiazoles in the presence of phosphorous oxychloride under the influence of microwave irradiation and conventional route has been described. The structures of oxadiazoles formed were confirmed by elemental and spectral analysis. In comparison with conventional microwave assisted method is simple, rapid and efficient. The title compounds were tested for analgesic activity by tail flick method and the series of 20 compounds was subjected for 3D QSAR analysis using V life MDS 3.5 software. The compounds were divided into training and test set. Best QSAR model was selected on the basis of various statistical parameters like square correlation coefficient (r2), cross validated square correlation coefficient (q2), standard error of estimation (SE) and sequential Fischer test (F). 3D QSAR study reveals that electronegative and bulk substitution at second and fifth position of 1, 3, 4-oxadiazole improves the analgesic activity.