A regioselective route to 5-substituted pyrazole- and pyrazoline-3-phosphonic acids and esters
作者:P. Conti、A. Pinto、L. Tamborini、V. Rizzo、C. De Micheli
DOI:10.1016/j.tet.2007.04.027
日期:2007.6
The regioselective synthesis of 5-substituted-3-dimethoxyphosphono-pyrazoles and -2-pyrazolines has been accomplished through the 1,3-dipolar cycloaddition of a suitable nitrile imine to monosubstituted alkynes and alkenes. Examples of hydrolysis of the heterocyclic phosphonic esters to the corresponding acids are described.