Article
Microwave-assisted synthesis of new N₁,N₄-substituted thiosemicarbazones
Registro en:
REIS, Camilla Moretto dos; et al. Microwave-Assisted Synthesis of New N1,N4-Substituted Thiosemicarbazones. Moleculaes, v.16, p.10668-10684, 2011.
1420-3049
10.3390/molecules161210668
Autor
Reis, Camilla Moretto dos
Pereira, Danilo Sousa
Paiva, Rojane de Oliveira
Kneipp, Lucimar Ferreira
Echevarria, Aurea
Resumen
We present an efficient procedure for the synthesis of thirty-six N₁,N₄-substituted thiosemicarbazones, including twenty-five ones that are reported for the first time, using a microwave-assisted methodology for the reaction of thiosemicarbazide intermediates with aldehydes in the presence of glacial acetic acid in ethanol and under solvent free conditions. Overall reaction times (20-40 min when ethanol as solvent, and 3 min under solvent free conditions) were much shorter than with the traditional procedure (480 min); satisfactory yields and high-purity compounds were obtained. The thiosemicarbazide intermediates were obtained from alkyl or aryl isothiocyanates and hydrazine hydrate or phenyl hydrazine by stirring at room temperature for 60 min or by microwave irradiation for 30 min, with lower yields for the latter. The preliminary in vitro antifungal activity of thiosemicarbazones was evaluated against Aspergillus parasiticus and Candida albicans.