title: Microwave-assisted synthesis of new N₁,N₄-substituted thiosemicarbazones.
abstract: 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.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, 23890-000, Seropédica, Rio de Janeiro, Brazil.
authors.forename: Camilla Moretto dos
authors.initials: CM
authors.lastname: Reis
authors.forename: Danilo Sousa
authors.initials: DS
authors.lastname: Pereira
authors.forename: Rojane de Oliveira
authors.initials: Rde O
authors.lastname: Paiva
authors.forename: Lucimar Ferreira
authors.initials: LF
authors.lastname: Kneipp
authors.forename: Aurea
authors.initials: A
authors.lastname: Echevarria
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000737:chemistry; D001230:Aspergillus / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D002625:Chemistry, Organic / Q000379:methods*; D008826:Microbial Sensitivity Tests; D008872:Microwaves; D013696:Temperature; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013997:Time Factors
chemical_list: D013882:Thiosemicarbazones; D000171:Acrolein; C012843:cinnamaldehyde