An Expeditious Synthesis of 1,2,4-Triazolo[1,5-<i>a</i>]Pyrimidine

Abstract

A simple, efficient, and diversity oriented synthesis of library of 1,2,4-triazolo [1,5-a]pyrimidine was undertaken using 5-amino,1,2,4-triazole as a building block. The synthesized analogues were fully characterized by known spectroscopic techniques like FT-IR, 1 H NMR, 13 C NMR, and mass spectroscopy. INTRODUCTIONOne-pot multi-component reactions ( Thus in view of finding novel analogues of triazole[1,5-a]pyrimidine with potential biological activities, we set upon a synthetic program involving 5-amino,1,2,4-triazole as building block. Although different strategies have been employed for the synthesis of these compounds, [11][12][13][14][15] these methods suffer from drawbacks such as long reaction times, cumbersome isolation of the products and harsh reaction conditions. Herein, we report a facile and efficient multi-component synthesis of 1,2,4-triazolo[1,5-a]pyrimidine in excellent yields from 3-amino-1,2,4-triazole, aldehydes and ethyl 3-oxo hexanoate respectively by simple fusion followed by adding catalytic amount of dimethylformamide (Scheme 1). Synthesis of fifteen novel analogues of 1,2,4-triazolo[1,5-a]pyrimidines containing an appropriate 1,3-bifunctional synthon has been undertaken. The structures of all the newly synthesized compounds were elucidated by FT-IR, mass spectra, 1 H NMR, 13C NMR and elemental analysis.