Isolamento e caracterização de acil-tiossemicarbazidas como intermediários na síntese de compostos mesoiônicos Isolation and characterization of acyl-thiosemicarbazides as intermediates in mesoionic compounds synthesis

Abstract

1,3,4-thiadiazolium-2-aminides and their isomers 1,3,4-triazolium-2-thiolates have been synthesized via anhydroacylation reactions. This work presents a study by infrared monitoring of the reaction between substituted aroyl acid chlorides and 1,4-diphenylthiosemcarbazide. The intermediates and products were isolated, purified and charaterized by IR and 13C NMR spectroscopy. The increasing or decreasing in intensity of characteristic stretching bands indicated the rate dependence on the electronic nature of substituents. The results also demonstrate that 1,3,4-triazolium-2-thiolates are obtained in anhydrous conditions whereas presence of water leads to a mixture of the isomers.

Keywords

• mesoionic compounds
• infra-red study
• acyl-thiosemicarbazides