Regioselective synthesis of 1-methyl-3-hydroxy-5-perfluoroalkylpyrazoles by the addition of methylhydrazine to perfluoroalkylacetylenic esters
作者:Bruce C. Hamper
DOI:10.1016/s0022-1139(00)82607-x
日期:1990.6
1H,3H)pyrazoles has been developed. Treatment of perfluoroalkylacetylenic esters with methylhydrazine in methanol-water at 0° or in methylene chloride at low temperature leads to 1-methyl-3-hydroxy-5-perfluoroalkyl(1H,3H)pyrazoles in a regioselective manner. Structural assignments of the regioisomers are based on 13C nmr chemical shifts, long range carbon-fluorine and carbon-proton coupling. The effect
已开发出对1-甲基-3-羟基-5-全氟烷基(1H,3H)吡唑的区域选择性途径。在甲醇-水中于0°或在二氯甲烷中于低温下用甲基肼处理全氟烷基炔属酸酯会以区域选择性方式生成1-甲基-3-羟基-5-全氟烷基(1H,3H)吡唑。区域异构体的结构分配基于13 C nmr化学位移,远距离碳氟和碳质子偶合。讨论了乙炔结构对反应区域选择性的影响。