Mohamadpour F, Lashkari M. Three-component reaction of β-keto esters, aromatic aldehydes and urea/thiourea promoted by caffeine: A green and natural, biodegradable catalyst for eco-safe Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/tiones derivatives under solvent-free conditions. J. Serb. Chem. Soc. [Internet]. 2018 Jul. 2 [cited 2024 Apr. 30];83(6):673-84. Available from: https://shd-pub.org.rs/index.php/JSCS/article/view/5499