Efficient synthesis of 4-O- and C-substituted-7-azaindoles

6-Chloro-4-nitro- and 4,6-dichloro-1H-pyrrolo[2,3-b]pyridine are versatile building blocks that allow the synthesis of 4-substituted 7-azaindole derivatives by simple nucleophilic displacement of the 4-substituent. Herein, we report on their reaction with phenolates and activated methylene nucleophiles.