Síntese de alguns Pirazóis derivados do 3-trifluoracetil-4,5-diidrofurano e 3-trifluoracetil-5,6-diidro-4H-pirano

Abstract

This work presents a simple and versatile strategy for the synthesis of new 4 and N-sustituted 5-trifluoromethyl-pyrazoles. These compounds were obtained by the reaction of 3-trifluoroacetyl-4,5-dihydrofuran and 3-Trifluoroacetyl-5,6-dihydro-4Hpyran with heteroaryl(aryl/alkyl)hydrazines (RNHNH2, where R= COCH₂CN, (4- Py)CO, (3-Py)CO, 4-Py(2-Cl)CO e (4-SO₂NH₂)Ph), in the presence of trifluoroboroetherete in methanol, furnishing the respective 5-trifluoromethyl-4-alkyl-1N-sustitutedpyrazoles, in moderate yields (17-59%). The pyrazoles obtained in this study were identified by NMR 1H, NMR 13C and Mass Espectroscopy.