Green Synthesis of Spiropyranone 3-Aryl-4-Methylcoumarin Derivatives using Carbonyldiimidazole

A series of spiropyranone 3-aryl-4-methylcoumarin derivatives have been synthesized from monospiro-2-hydroxy acetophenone in a novel and efficient green method using imidazolyl intermediates and inorganic base. Imidazolyl intermediates were in turn generated by grinding the respective phenylacetic acid along with carbonyldiimidazole (CDI). Similarly, monospiro-2-hydroxy acetophenone derivatives were prepared selectively by avoiding formation of...