N-Acyl-3,3-difluoro-2-oxoindoles as versatile intermediates for the preparation of different 2,2-difluorophenylacetic derivatives

• Autor(a) principal: Boechat,Núbia
• Data de Publicação: 2008
• Outros Autores: Kover,Warner B., Bastos,Mônica M., Pinto,Angelo C., Maciel,Lindalva C., Mayer,Lúcia M. U., Silva,Filipe S. Q. da, Sá,Paula M., Mendonça,Jorge S., Wardell,Solange M. S. V., Arruda,Monique S. L.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000300011
• topic: isatins; DAST; deoxo-fluor; 1,3,4-thiadiazoles; 3,3-difluoro-2-oxoindoles; N-acyl-3,3-difluoro-2-oxoindoles

This paper describes the versatility of N-Acyl-3,3-difluoro-2-oxoindoles, obtained from the the reaction of N-acylisatins with (diethylamino)sulphur trifluoride (DAST) which, on opening of the heterocyclic ring by reactions with nucleophiles, lead to the formation of a variety of products: reaction with water yields 2-(2-amidoacyl)-2,2-difluoroacetic acids, with alcohols yields alkyl 2-(2-amidoacyl)-2,2-difluoroacetates, with amines and glycine yields 2-(2-amidoacyl)-2,2-difluoroacetamides and with thiosemicarbazides yields difluorothiosemicarbazide derivatives. The latter undergo acid-catalysed cyclizations to yield N-(2-((5-aminoaryl-1,3,4-thiadiazol-2-yl)difluoromethyl)-4-(R)-phenyl)acetamide. The X-ray structure of N-(2-((5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl)-4-methylphenyl)acetamide has been determined.