Novel Synthesis of 5-Amino-3-bromo-1-(<i>tert-</i>butyl)-1<i>H</i>-pyrazole-4-carbonitrile: A Versatile Intermediate for the Preparation of 5-Amino-3-aryl-1-(<i>tert-</i>butyl)-1<i>H</i>-pyrazole-4-carboxamides
作者:Mark A. Bobko、Arun C. Kaura、Karen A. Evans、Dai-Shi Su
DOI:10.1021/ol301655f
日期:2012.8.3
synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 has been devised. Preparation of pyrazole bromide 3 from potassium tricyanomethanide can be accomplished in only two steps in good yield and features a selective Sandmeyer reaction on the corresponding diaminopyrazole. This allows for a more versatile synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 than was previously