SYNTHESIS OF 3-SUBSTTTUTED BENZO[b]THIOPHENES VIA THE REACTION OF α-SUBSTITUTED 2-LITHIO-β-METHOXYSTYRENES WITH SULFUR

摘要

3-Substitued benzo[b]thiophenes were synthesized in reasonable overall yields from α-substituted 2-bromo-β-methoxystyrenes. Thus, the bromine-lithium exchange between these bromostyrenes with butyllithium in diethyl ether at 0 °C followed by reaction with sulfur afforded the corresponding α-substituted β-methoxy-2-sulfanylstyrenes. These were then treated with an equimolar amount of concentrated hydriodic acid in acetonitrile at room temperature to give the desired products.