1001519-38-5Relevant articles and documents
Improved regioselectivity in pyrazole formation through the use of fluorinated alcohols as solvents: Synthesis and biological activity of fluorinated tebufenpyrad analogs
Fustero, Santos,Roman, Raquel,Sanz-Cervera, Juan F.,Simon-Fuentes, Antonio,Cunat, Ana C.,Villanova, Salvador,Murguia, Marcelo
, p. 3523 - 3529 (2008/09/20)
(Chemical Equation Presented) The preparation of N-methylpyrazoles is usually accomplished through reaction of a suitable 1,3-diketone with methylhydrazine in ethanol as the solvent. This strategy, however, leads to the formation of regioisomeric mixtures of N-methylpyrazoles, which sometimes are difficult to separate. We have determined that the use of fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation, and we have used this modification in a straightforward synthesis of fluorinated analogs of Tebufenpyrad with acaricide activity.