To a solution of 7-chloro-3-methyl-pyrrolo[2,3-c]pyridine-1,4-dicarboxylic acid 1-tert-butyl ester (300 mg) in dimethylformamide (4 ml) was added 4-ethylmorpholine (492 ul), morpholine (172 ul), 1-hydroxybenzotriazole hydrate (204 mg) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (223 mg) and the solution stirred at room temperature overnight. The solution was diluted with ethyl acetate (50 ml). The organic layer was then washed with 5% sodium hydrogen carbonate solution (2×10 ml) and water (2×20 ml). The organic layer was dried (MgSO4) and evaporated to give an off-white foam (107 mg) which was used without further purification.
