Facile synthesis of some novel 4-{3-aryl-3,4-dihydro-2H-benzob1,4 thiazin-2-yl}-2H-chromen-2-one derivatives

摘要

A protocol for chemoselective one pot synthesis of 4-{3-aryl-3,4-dihydro-2H-benzobl ,4thiazin-2-yl)-2H-chromen-2-ones 4 and 4-{3-aryl-3,4-dihydro-2H-benzobl,4thiazin-2-yl)-2H-chromen-2-ones 6 under refluxing conditions has been developed.Starting from 4-bromomethylcoumarin and Schiff base,which is derived from o-aminothiophenol and substituted aromatic aldehydes,the inter-mediate sulfide spontaneously underwent intramolecular carbanion addition across the azomethine carbon.