Regioselective Synthesis of Thieno[3,2-c][1]benzopyran-4-ones by Thio-Claisen Rearrangement
作者:Krishna C. Majumdar、Anindita Biswas
DOI:10.1007/s00706-003-0164-4
日期:2004.8
A number of thieno[3,2- c ][1]benzopyran-4-ones, potential antiinflamatory, antipyretic, and antiallergic drugs, are synthesized in 65–80% yield by thermal thio- Claisen rearrangement of 4-allylthio[1]benzopyran-2-ones in refluxing quinoline for 0.5–8.0 h. The 4-allylthio[1]benzopyran-2-ones are in turn prepared in 75–85% yield from 4-mercaptocoumarin and different allylic halides by phase-transfer-catalysed