A one-pot, three-component aminotriazine annulation onto 5-aminopyrazole-4-carbonitriles under microwave irradiation

A one-pot, three-component, microwave-assisted reaction of 5-aminopyrazole-4-carbonitriles, triethyl orthoformate and cyanamide afforded novel 7-arylamino-substituted 4-aminopyrazolo[1,5-a][1,3,51 triazine-8-carbonitriles. The reaction proceeded in a chemo- and regioselective manner resulting in the successful amino-1,3,5-triazine annulation onto 5-aminopyrazole-4-carbonitriles to give 4-aminopyrazolo [1,5-a][1,3,5]triazine-8-carbonitriles. The operational simplicity of the method and high purity of the products, which can be isolated via simple filtration, make this approach attractive for the preparation of a library of compounds for drug discovery processes. (C) 2014 Elsevier Ltd. All rights reserved.