720672-82-2Relevant academic research and scientific papers
Facile metal-free synthesis of 3-aryl-4-substituted coumarins from o-hydroxy carbonyl compounds
Taksande, Kiran,Borse,Lokhande, Pradeep
experimental part, p. 2284 - 2290 (2010/09/17)
The intramolecular cyclization of the esters of salicylaldehyde, O-hydroxyacetophenones, methyl salicylate, and 2'-hydroxy chalcones by potassium hydroxide in pyridine leads to a short and convenient synthesis of 3,4-disubstituted coumarins. Twenty 3-phenyl coumarins were synthesized in 80-90% yields. No other by-product, such as 2-benzylchromone or-diketones, was observed the reactions. The mild reaction condition involves the removal of more acidic benzylic proton, which leads to a relatively cheap, nontoxic, metal-free method for the synthesis of 3-aryl-4-substituted coumarins. Copyrigh
