A Convenient Approach to the Synthesis of Novel Tricyclic Fused Furo[2,3-b]pyridine Derivatives

Abstract

The synthesis of novel tricyclic fused furo[2,3-b]pyridine derivatives is described. 3-Cyano-4,5-dihydro-2-furan(and 2-thiophene)acetonitriles 1,2 were reacted with phenacyl bromides to give 5'-arylfuran-2'-amines 3,4. Compounds 3,4 were intramolecularly cyclized in the presence of sodium ethoxide to yield tricyclic fused furo[2,3-b]pyridine derivatives 5,6. Furthermore, one-pot synthesis of compounds 5,6 from starting materials 1,2 is also developed.