Synthesis of New 1<i>H</i>-Indazoles through Diels-Alder Transformations of 4-Styrylpyrazoles under Microwave Irradiation Conditions
作者:Vera L. M. Silva、Artur M. S. Silva、Diana C. G. A. Pinto、José Elguero、José A. S. Cavaleiro
DOI:10.1002/ejoc.200900513
日期:2009.9
Microwaveirradiationunder solvent-free conditions induces 1-acetyl-4-styrylpyrazoles to undergo Diels–Alder cycloaddition reactions with N-methyl- or N-phenylmaleimide to give tetrahydroindazoles in good yields and with high selectivities. With conventional heating, these reactions either do not occur or afford only traces of the cycloadducts. These cycloadducts were then converted into the corresponding