Microwave-assisted organic synthesis has been widely studied and deliberated, opening up some controversial issues as well. Nowadays, microwave chemistry is a mature technology that has been well demonstrated in many cases with numerous advantages in terms of the reaction rate and yield. The strategies toward scaling up find an ally in continuous-flow reactor technology comparing dielectric and conductive heating.

The impressive pharmacological properties shown by a number of coumarins have led to extraordinarily large emphasis being placed on the design of more efficient and greener synthetic procedures to produce them.

The syntheses of almost all N-heterocycles have now been successfully performed under microwave irradiation and have provided significant improvements in the reaction time and efficiency. The peculiar properties of dielectric heating give it the ability to strongly promote cyclocondensation, cycloaddition and selective N-heterocycle functionalisation and it has, therefore, very much caught the attention of the medicinal chemistry community. In this work, we present an overview of recent literature and technical advances in this research field with the aim of providing insight into the applications of microwave-assisted synthesis in the preparation of the main drug categories that contain N-heterocycle scaffolds.