Microwave-Assisted Sequential One-Pot Synthesis of 8-Substituted Pyrazolo[1,5-a][1,3,5]triazines

This paper reports a convenient sequential one-pot approach for the synthesis of an array of 14 pyrazolo[1,5-a][1,3,5]triazines, substituted in C8 by halogen (Br), various functions (CN and CO2Et) and alkyl or (het)aryl groups. This study confirms the interest of combining the efficient heating obtained under dielectric microwave heating and the achievement of sequential one-pot reactions, avoiding the tedious work-up and purification of intermediate compounds, achieving sustainable synthesis processes. Considering usual conventional methods, this microwave protocol is featured by advantages in terms of yields, reaction times, and convenient gram scale synthesis.

Automated summary

This paper describes a convenient sequential one-pot approach for the synthesis of a series of 14 pyrazolo[1,5-a][1,3,5]triazines, with advantages in terms of yields, reaction times, and convenient gram scale synthesis compared to traditional methods. The combination of efficient heating using dielectric microwave heating and sequential one-pot reactions eliminates the need for laborious work-up and purification of intermediate compounds, allowing for sustainable synthesis processes.