Pyrrolopyridine and Isoindole as Potential Anticonvulsant Agents: Design, Synthesis, and Pharmacological Evaluation

Background and Objective: Phthalimide, as the rigid form of ameltolide, exhibits a phenytoin-like profile of drug-receptor interaction and is active in the MES model and inactive in the PTZ model as an anti-epileptic agent. In this research, based on the isosteric replacement, we reported the design, preparation, and antiepileptic activity of 13 new analogs of pyrrolopyridine and isoindole. Methods: The designed compounds were prepared by condensing 3, 4-pyridine dicarboxylic anhydride, or 4-fluorophthalic anhydride with different aryl amines. MES and PTZ-induced seizure models were utilized to evaluate the antiepileptic effect of the prepared ligands. Results: It was found that the prepared ligands have significantly affected both tonic and clonic seizures. In tonic seizures, the prepared compounds decreased mortality to a significant extent, and in clonic seizures, they significantly showed better frequency and latency. Compounds 9, 12, and 13 were the most potent ligands than phenytoin. Conclusion: It is concluded that the best distance between two aryl parts is two bonds, and the substitution of the nitro group at the meta position of the phenyl ring is better than the para position. Our research group has investigated this concept for designing newer compounds with better anticonvulsant activity.