Synthesis of 2-substituted-7-azaindoles from 2-amino-3-picolin

Abstract An easy route to the synthesis of 2-substituted-7-azaindole derivatives has been developed. The carbinol intermediate dissolved in DMF undergoes cyclization upon treatment with sodium hydride, trifluoroacetic anhydride, and trifluoroacetic acid at 120 °C in a straightforward and one-pot step. An alternative methodology using (CF 3 SO 2 ) 2 O in acetonitrile in basic media followed by the addition of CF 3 COOH affords the expected 2-substituted azaindole in best yields.