New Facile Route to Synthesize Furo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidine and Furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine Derivatives

Abstract

A new facile route for synthesis of 3-(aryl)-8,9-diphenylfuro[3,2-e][1,2,4]triazolo pyrimidines derivative from the same starting material, 2-amino-4,5-diphenylfuran-3-carbonitrile, has been developed through heterocyclization of the corresponding arylidene-hydrazono-5,6-diphenylfuro[2,3-d]pyrimidine and N-(arylmethylene)-4-imino-5,6-diphenylfuro[2,3-d]pyrimidin-3(4H)-amine under refluxing condition with acetic anhydride followed by air oxidation. The products were obtained in good yield with an easy workup along with the purification of products by a nonchromatographic method. This general synthetic procedure can be extended to the preparation of a wide range of isomeric triazoles using 2-amino 3-carbonitrile bifunctional derivatives.

GRAPHICAL ABSTRACT

Keywords:

• Acetic anhydride
• air oxidation
• 2-(aryl)-8,9-diphenylfuro[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines
• 3-(aryl)-8,9-diphenylfuro[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines
• arylidene-hydrazono-5,6-diphenylfuro[2,3-d] pyrimidines
• heterocyclization
• N-(arylmethylene)-4-imino-5,6-diphenylfuro[2,3-d]pyrimidin-3(4H)-amines

ACKNOWLEDGMENTS

The authors sincerely thank Dr. Lari, Dr. Vahedi, and Mr. Imanpour for their support, encouragement, and helpful discussions.