Synthesis of 5-Aminopyrazole-4-carbonitriles

A one-pot reaction between substituted hydrazines, malononitrile and triethyl orthoformate leads directly to the formation of 1-substituted 5-aminopyrazole-4-carbonitriles. The scope and limitations of this synthetic procedure are discussed in relation to the well established synthesis of these compounds via substituted hydrazines and ethoxymethylenemalononitrile.