An efficient method for one-pot synthesis of 3-alkoxy-substituted chromeno[4,3-b]pyrrol-4(1H)-one derivatives

摘要

A one-pot two-step reaction of 4-aminocoumarin with arylglyoxal monohydrates and p-toluenesulfonates has been developed, which offers 3-alkoxy-substituted chromeno[4,3-b]pyrrol-4(1H)-ones in moderate to good yields. At first, arylglyoxal monohydrates and 4-aminocoumarin were converted into 3-hydroxychromeno[4,3-b]pyrrol-4(1H)-one intermediates in AcOH under reflux. Then the title compounds in an in situ reaction of the intermediates with p-toluenesulfonates catalyzed by DBU in refluxing toluene were obtained.