Dimethylformamide → 7-bromo-5-(trifluoromethyl)-1H-indole-3-carbaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Phosphorus oxychloride (1.029 ml, 11.04 mmol) was added dropwise to DMF (8 ml) at 0° C. The mixture was stirred 30 min at 0° C. and 7-bromo-5-(trifluoromethyl)-1H-indole (2.65 g, 10.04 mmol) in DMF (2 mL) was added dropwise. The cooling bath was removed and the reaction was stirred at ambient temperature for 3 hours. The reaction was quenched with ice (5 g) and aqueous sodium hydroxide (1N, 20 mL). The reaction was extracted with ethyl acetate (2×30 mL) and the organic phase was dried with MgSO4 and evaporated. The residue was purified by chromatography on SiO2 with a 5%-60% gradient of ethyl acetate/hexanes. The product 7-bromo-5-(trifluoromethyl)-1H-indole-3-carbaldehyde (2.17 g, 7.43 mmol, 74.0% yield) was obtained as a white solid. 1H-NMR (CDCl3, 400 MHz) δ 10.09 (s, 1H), 9.06 (s, 1H), 8.59 (s, 1H), 8.00 (d, J=3.2 Hz, 1H), 7.72 (d, J=3.0 Hz, 1H). LC/MS (HPLC method 4): tR=3.29 min, 292.06(MH)+.

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