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

A simple, novel, and efficient route for the synthesis of 5-amino-3-aryl-1-(<i>tert</i>-butyl)-1<i>H</i>-pyrazole-4-carboxamides <b>1</b> has been devised. Preparation of pyrazole bromide <b>3</b> 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-(<i>tert</i>-butyl)-1<i>H</i>-pyrazole-4-carboxamides <b>1</b> than was previously possible