Efficient Methods for the Synthesis of Novel Arylazothiazoles Based on Acetylferrocene or Adamantane.

BACKGROUND: Hydrazonoyl halides are convenient for the synthesis of arylazothiazoles
Results: A series of novel arylazothiazoles were efficiently synthesized from the reaction of hydrazonoyl chlorides with 2-(adamantan-2-ylidene)hydrazinecarbothioamide or 2-(ferrocenyl-1-ylidene)hydrazinecarbothioamide in dioxane is used as aprotic solvent, because of its lower toxicity and higher boiling point (101 °C) and triethylamine at reflux. The reaction mechanistic pathway proceeded by the nucleophilic substitution reaction by elimination of hydrogen chloride to give thiohydrazonates as intermediate, which in situ undergo intramolecular cyclization and loss of water molecule to afford the final product of novel arylazothiazoles. This method is simple, good yield and excellent purities. The synthetic schemes for the final Products are proposed and discussed. The chemical structures of the final products were identified by different techniques, such as elemental analysis, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS).
CONCLUSION: In this article, we prepared arylazothiazoles from the reaction of 2-(adamantan-2-ylidene)hydrazinecarbothioamide or 2-(ferrocenyl-1-ylidene)hydrazinecarbothioamide with hydrazonoyl halides. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.