Concentrated solar radiation as a renewable heat source for a preparative-scale and solvent-free Biginelli reaction†
A well-known Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones was performed in an environmentally responsible manner. Large numbers of substrates were screened, and found to give excellent yields of the desired products. In addition to the synthesis of drug molecules, the reaction was easily scaled up to 50 mmol. The present method was also energy efficient and saved more than 95% of energy when compared to conventional methods.