New Hydrazides and Thiosemicarbazides Derived from Ethylenedioxythiophene as Potential Anticonvulsants

Abstract

A series of ethyl 7-({2-[(substituted)carbonyl]hydrazino}carbonyl)-2,3-dihydrothieno [3,4-b][1,4]dioxine-5-carboxylates (5–13) and ethyl 7-{[({2-[(substituted)carbonyl]hydra-zino}carbonothioyl)amino]carbonyl}-2,3-dihydrothieno[3,4-b][1,4]dioxine-5-carboxy-lates (15–20) were synthesized in good yield by condensing ethyl-7-(chlorocarbonyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine-5-carboxylate (4) with suitable hydrazides. The newly synthesized compounds were characterized using FTIR, ¹H NMR, ¹³C NMR, mass spectroscopy, and elemental analyses. The anticonvulsant activity of all the title compounds was investigated against maximal electroshock-induced seizures (MES) and pentylenetetrazole (PTZ)-induced convulsion models. None of the compounds showed toxicity at the maximum dose of 2000 mg/kg. Almost all the compounds showed protection in flexion and extension stage against induced convulsion. Among them, naphthyloxy-substituted derivatives exhibited very good response against induced seizures.

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Keywords:

• Anticonvulsant
• hydrazide
• MES
• PTZ
• thiophene
• thiosemicarbazide

Acknowledgments

The authors are thankful to the Head, SAIF, CDRI, Lucknow, India, and the Chairman, NMRRC, IISc, Bangalore, India, for providing mass, ¹H NMR, and ¹³C NMR spectral data.