Straightforward transformation of isoxazoles into pyrazoles: renewed and improved
作者:Sergey I. Sviridov、Andrei A. Vasil'ev、Sergey V. Shorshnev
DOI:10.1016/j.tet.2007.09.046
日期:2007.12
or carbamoyl groups were transformed into the corresponding pyrazoles in high yields by the treatment with hydrazine in methanol in the presence of a hydrogenation catalyst, e.g., Raney nickel, at ambient temperature. For the synthesis of N-substituted pyrazoles, hydrogenolysis of isoxazole followed by the treatment with substituted hydrazine was required. 3(5)-Aryl- or acylamido-substituted isoxazoles
通过在环境温度下在氢化催化剂例如阮内镍的存在下用肼在甲醇中处理,将具有烷基或氨基甲酰基的异恶唑高产率地转化成相应的吡唑。为了合成N-取代的吡唑,需要将异恶唑氢解,然后用取代的肼处理。3(5)-芳基或酰基酰胺基取代的异恶唑不太适合这种转化。