Synthesis and Characterization of Novel Polythiadiazoles from Bis-Hydrazonoyl Dichlorides and Bis-(methyl-2-arylidene Hydrazone Carbodithioates

Title:Synthesis and Characterization of Novel Polythiadiazoles from Bis-Hydrazonoyl Dichlorides and Bis-(methyl-2-arylidene Hydrazone Carbodithioates

Volume: 22 Issue: 3

Author(s): Abdelwahed R. Sayed*Jeffrey S. Wiggins*

Affiliation:

• School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi, 39406, Unites States
• Department of Chemistry, Faculty of Science, Beni-Suef University, Beni-Suef, 62514, Egypt

• School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi, 39406, Unites States

Keywords: Bis-hydrazonoyl, bis(methyl-2-arylidenehydrazone-carbodithioates), hydrazones, thiadiazoles, cycloadduct, nitrilimine.

Abstract:

Background: Thiadiazoles exhibit a variety of biological activities, including antimicrobial, antiviral, antituberculosis, carbonic anhydrase inhibitor, antitrypanosomal agent, and anticonvulsant properties.

Methods: The new polymers are made in two distinct stages. The first stage is to prepare the starting material bis-(methyl-2-arylidenehydrazone-carbodithioates) via a condensation reaction between methyl-hydrazinecarbodithioate and dicarbonyl compounds in suitable solvent as isopropyl alcohol. The second stage for the synthesis of the final products poly(1,3,4-thiadiazoles) derivatives is the suitable bis-hydrazonoyl chloride reacted with an equal molar ratio of bis-(me-thyl-2-arylidenehy-drazonecarbodithioates) in dimethyl sulfoxide, with triethylamine and reflux until the methanethiol gas stopped evolving. FT-IR (Fourier transform infrared spectroscopy), NMR (Nuclear magnetic resonance), and thermal investigation were used to identify and characterize the final products.

Results: This work effectively synthesized new derivatives of poly(1,3,4-thiadiazoles) in good yields via the reaction of bis-hydrazonoyl dichlorides with bis-(methyl-2-arylidenehydrazone-carbodithioates). Two routes can be used to explain how the final poly(1,3,4-thiadiazoles) com-pounds are formed. The first route can be explained by nucleophile substitution of thiolate of bis(methyl-2-arylidenehydrazonecarbodithioates) to the chlorinated carbon of bis-hydrazonoyl dichlorides, followed by removal of HCl (hydrochloric acid) to provide an intermediate (S-al-kylated). This intermediate at once leads to an intramolecular cyclo-polycondensation by the exclusion of methanethiol gas to produce our ending products poly(1,3,4-thiadiazoles). The second route concluded [3+2] cycloaddition of 1,3-dipolar cycloadditions of nitrilimines (generated in situ by treatment of bis-hydrazonoyl dichlorides with triethylamine) to thione (C=S) followed by removal of methanethiol to give poly(1,3,4-thiadiazoles) as depicted in schematic diagram.

Conclusion: In this article, we reported an efficient method for the synthesis of the novel poly(1,3,4-thiadiazoles) from the reaction of bis-(methyl-2-arylidenehydrazonecarbodithioates) with bis-hydrazonoyl halides.

Cite this article as:

Sayed R. Abdelwahed*, Wiggins S. Jeffrey*, Synthesis and Characterization of Novel Polythiadiazoles from Bis-Hydrazonoyl Dichlorides and Bis-(methyl-2-arylidene Hydrazone Carbodithioates, Current Organic Synthesis 2025; 22 (3) . https://dx.doi.org/10.2174/0115701794287942240614070341