Synthetic Procedures and Chemical Reactions for Thiocarbohydrazide: An Overview

Abstract

This study investigated different techniques for producing thiocarbohydrazide (1) through the reaction of hydrazine hydrate and carbon disulfide, using either water or methanol as a solvent. The results showed that switching from water to methanol as the reaction mixture led to a high yield of thiocarbohydrazide (96% based on [hydrazine]). Additionally, the reactivity of thiocarbohydrazide (1) in the synthesis of various heterocycles containing sulfur was further examined in this study. This can be accomplished by combining thiocarbohydrazide (1) with aldehydes, where the product obtained depends on the amount of aldehyde used. Additionally, 1 reacts with acetyl acetone (6), forming 3,5-dimethylpyrazole derivative 7. Furthermore, thiocarbohydrazide 1 reacted with substituted isatin derivatives 11a–d to form bis-isatin derivatives 12a–d. The amino-pyrazolotriazole derivative 16 is synthesized by heating thiocarbohydrazide (1) and ethyl cyano- acetate, resulting in the removal of ethanol and water molecules. When using DMF as a solvent, the reaction between thiocarbohydrazide (1) and carboboxylic acids (19) can be carried out using either microwave or thermal reflux heating methods, yielding substituted 3-mercapto-1,2,4-triazoles 20. However, thermal reflux heating produces a higher yield, despite taking longer than the microwave method. Compound 1 underwent reactions with diacetyl, phenylglyoxal hydrate, and benzil, resulting in the formation of monohydrazone 22 and 5-hydroxy-triazine-3-thione 26a,b. Additionally, the interactions of thiocarbohydrazide (1) with malononitriles, quinoxalines, carbonyl cyanides, coumarin derivatives, and oxazinone derivatives were investigated in this study. This review covers the synthesis and reactions of thiocarbohydrazide (1) from 2005 to the present.