6-bromo-1H-indole-2-carbaldehyde

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium hydride (60% weight dispersion in mineral oil, 80.0 mg, 1.98 mmol) was added to a solution of 6-bromo-1H-indole-2-carbaldehyde (371 mg, 1.66 mmol) in DMF (10.0 mL) at 0° C. under N2. Methyl iodide (0.124 mL, 1.98 mmol) was added, and the reaction mixture was allowed to warm slowly to room temperature. After stirring for 4 h, the mixture was quenched with H2O at 0° C., upon which a solid precipitated out of solution. The slurry was extracted with ethyl ether (3×). The combined organic layers was dried over Na2SO4, filtered and concentrated to give the title compound (422 mg, 99%) as a yellow solid: 1H NMR (500 MHz, CDCl3) δ 9.89 (s, 1H), 7.59 (d, J=9.0 Hz, 2H), 7.28 (dd, J=8.5, 2.0 Hz, 1H), 7.22 (s, 1H), 4.07 (s, 3H). the mixture was quenched with H2O at 0° C., upon which a solid precipitated out of solution The slurry was extracted with ethyl ether (3×) The combined organic layers was dried over Na2SO4 filtered concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of (6-bromo-1H-indol-2-yl)methanol (696 mg, 3.00 mmol) in THF (25.0 mL) was added MnO2 (3.20 g, 37.0 mmol) at 0° C. The reaction mixture was stirred for 24 h at room temperature. The reaction mixture was filtered through Celite, and the filtrate was concentrated under reduced pressure to give the title compound (371 mg, 55%) as an orange solid: 1H NMR (500 MHz, CDCl3) δ 9.86 (s, 1H), 9.07 (br s, 1H), 7.64 (s, 1H), 7.61 (d, J=8.5 Hz, 1H), 7.29 (dd, J=8.5, 1.5 Hz, 1H), 7.24 (d, J=1.0 Hz, 1H). The reaction mixture was filtered through Celite the filtrate was concentrated under reduced pressure