Silica gel has been used for synthesis of biscoumarin derivatives starting from 4-hydroxycoumarin and aryl aldehydes. The reaction conditions are completely in agreement with green chemistry principles including sing water as media and a recyclable and safe catalyst. This method is also simple and inexpensive and leads to high yield of products in short reaction […]
Molybdate sulfuric acid (MSA) has been prepared and used as catalyst for the Biginelli synthesis of some quinazolinones/thiones under solvent-free conditions. The catalyst loading is low and it shows recyclability. This method has advantages such as avoidance of the organic solvents, high yield of pure products, short reaction times and operational simplicity.