Dimethylformamide → tert-Butyl 4-bromo-1H-pyrrolo[2,3-b]pyridine-1-carboxylate

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Reaction Conditions

Reaction Steps

4-Bromo-1H-pyrrolo[2,3-b]pyridine. A solution of trifluoromethyl sulfonic anhydride (9.3 g, 33 mmol) was added dropwise to a mixture of 1H-pyrrolo[2,3-b]pyridine 7-oxide (3 g, 22 mmol) and tetrabutyl ammonium bromide (10.8 g, 33 mmol) in N,N-dimethylformamide (30 mL) at 0° C. The resulting mixture was stirred at 0° C. for 4 h and at room temperature overnight. The reaction was quenched with water and neutralized with 1N sodium hydroxide to pH=7. The resulting mixture was extracted twice with a mixture of methylene chloride and i-propanol (30 mL, Vm:Vp=4:1). The organic layer was combined, dried over anhydrous sodium sulfate, concentrated and purified by a reverse-phase preparatory HPLC (0-30%: acetonitrile+0.1% TFA in water+0.1% TFA, over 15 min.) to give the title compound (1.5 g, 34.3% yield). MS(ESI) m/z 196.8 [M+1]+, 198.8 [M+3]+.

Provenance & Evidence