DAST promotes the synthesis of new 5-(trifluoromethyl)-3-(1, 1-difluoroethan-2-yl)-1H-pyrazoles

HG Bonacorso, LMF Porte, CA Cechinel, GR Paim…

Index: Bonacorso, Helio G.; Porte, Liliane M.F.; Cechinel, Cleber A.; Paim, Gisele R.; Deon, Everton D.; Zanatta, Nilo; Martins, Marcos A.P. Tetrahedron Letters, 2009 , vol. 50, # 13 p. 1392 - 1394

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Citation Number: 27

Abstract

This study describes, firstly, the synthesis of a new precursor, 4, 6, 6-trimethoxy-1, 1, 1- trifluorohex-3-en-2-one (1), from the trifluoroacetylation reaction of 1, 1, 3, 3- tetramethoxybutane, in 65% yields. Afterwards, the reaction of 1 with two hydrazines (NH2NHR, where R= 2-furanoyl, C6F5) led to a new series of 4, 5-dihydro-1H-pyrazoles, containing an acetal-protected aldehyde function as substituent, in 90–97% yields. In a ...