Synthesis of 5-substituted 1-aryl-1<i>H</i>-pyrazole-4-acetonitriles, 4-methyl-1-phenyl-1<i>H</i>-pyrazole-3-carbonitriles and pharmacologically active 1-aryl-1<i>H</i>-pyrazole-4-acetic acids
作者:Giulia Menozzi、Pietro Schenone、Luisa Mosti、Franceses Mattioli
DOI:10.1002/jhet.5570300427
日期:1993.7
Lithium aluminum hydride reduction of 5-substituted or unsubstituted ethyl or methyl 1-aryl-1H-pyrazole-4-carboxylates gave, generally in excellent yields, 5-substituted or unsubstituted 1-aryl-1H-pyrazole-4-methanols which afforded the corresponding 1-aryl-4-(bromomethyl)-1H-pyrazoles with hydrobromic acid in acetic acid solution. These crude intermediates gave by reaction with potassium cyanide in
氢化铝锂还原5-取代或未取代的乙基或甲基1-芳基-1 H-吡唑-4-羧酸酯通常以优异的收率得到5-取代或未取代的1-芳基-1 H-吡唑-4-甲醇在乙酸溶液中用氢溴酸得到相应的1-芳基-4-(溴甲基)-1 H-吡唑。这些粗中间体仅在未取代的化合物为5的情况下与氰化钾在二甲亚砜溶液中形成的芳基1-芳基-1 H-吡唑-4-乙腈,否则为5取代的1-芳基-1 H-吡唑-4的混合物通常获得-乙腈和4-甲基-1-苯基-1 H-吡唑-3-腈。乙腈通过碱水解,IIIa,b,i,1以优异的产率得到相应的1-芳基-1 H-吡唑-4-乙酸Va,b,i,l。化合物Vb,i,l在扭体试验中显示出明显的镇痛特性,与低急性毒性有关;此外,化合物VI在角叉菜胶诱导的水肿测定中显示出统计学上显着的抗炎活性。