New 6-bromoimidazo[1,2-a]pyridine-2-carbohydrazide derivatives: synthesis and anticonvulsant studies

In the present work, we report the facile synthesis and anticonvulsant study of new imidazo[1,2-a]pyridines carrying biologically active hydrazone functionality (3a–3e) and suitably substituted 1,2,4-triazole moieties (4, 5a–5d, 6, and 7a–7d). The newly synthesized intermediates and final compounds were characterized by various spectral techniques such as FTIR, 1H NMR, 13C NMR, and mass spectral and elemental analysis studies. The in vivo anticonvulsant study of the target compounds were carried out following maximal electroshock seizure and subcutaneous pentylene tetrazole methods, while their toxicity study was performed following rotarod method by taking 20, 40, and 100 mg/kg dose levels. Most of the new compounds displayed remarkable anticonvulsant properties at these doses. Particularly, compounds 3b and 4 carrying hydrogen bond donor groups, viz. hydroxyl and amine moieties respectively, exhibited complete protection against seizure and their results are comparable to that of standard drug diazepam. Further, the motor impairment study revealed that all the compounds are nontoxic upto 100 mg/kg.