1,1-Dibromoethane → 3-(1H-Pyrrolo[2,3-b]pyridin-5-yl)-azetidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

In an inert atmosphere, zinc dust (223 mg, 3.41 mmol) was vigorously stirred in dimethylacetamide (1.5 ml) and heated to 65° C. Subsequently, trichloromethylsilane (50 μl, 0.38 mmol) and dibromoethane (30 μl, 0.38 mmol) were added, and the reaction mixture was stirred for further 30 minutes at 65° C. 3-Iodo-azetidine-1-carboxylic acid tert-butyl ester (462 mg, 1.89 mmol) in dimethylacetamide (2 ml) was added dropwise to the above prepared solution at 65° C. and stirred for 30 minutes. 5-Iodo-1H-pyrrolo[2,3-b]pyridine (697 mg, 2.46 mmol) in dimethylacetamide (4 ml) was added to the reaction mixture. Subsequently, [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium(II)-dichlormethane (93 mg, 0.11 mmol) and copper(I)iodide (108 mg, 0.57 mmol) were added. The reaction mixture was heated to 85° C. for 5 hours, cooled to room temperature, diluted with ethyl acetate and filtered over Celite. The residue was extracted 3 times with water. The organic layer was dried over magnesium sulphate, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (EtOAc:cylcohexane) to afford the title compound (104 mg, 20% yield).

Provenance & Evidence