Synthesis of some trifluoromethyl substituted 1-methylpyrazoles
作者:James W. Pavlik、Theppawut Israsena Na Ayudhya、Supawan Tantayanon
DOI:10.1002/jhet.5570400619
日期:2003.11
reaction of β-alkoxyvinyl trifluoromethyl ketones 1a-c with methylhydrazine (2) in absolute ethanol are the 3-(trifluoromethyl)-substituted-1-methylpyrazoles 3a-3c with lesser amounts of the 5-(trifluoromethyl)-substituted products 4a-4c and 5a-5c. Carrying out the reaction in non-polar, aprotic solvents can further enhance the regioselectivity favoring the 3- (trifluoromethyl) -substituted isomers.