Water → 6-chloro-7-fluoro-1H-indole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

Add phosphorus oxychloride (0.94 g, 6.16 mmol) to DMF (12 mL, cooled in an ice bath) with vigorous stirring. After about 10 minutes, add 6-chloro-7-fluoro indole (0.93 g, 5.6 mmol) in anhydrous DMF (4 mL), stir at 0° C. for 1 hour, warm to room temperature and stir overnight at room temperature (−16 hrs). Treat with 14.0 mL of 2N NaOH (4 eq.) with vigorous stirring. Heat the reaction to 80° C. for half an hour then cool. Pour the reaction into cold water with vigorous stirring to give a solid. Collect the solid by filtration and dry overnight in a vacuum oven at room temperature, to give the title compound: 1H NMR (300 MHz, CD3COCD3/CDCl3) 7.09 (t, 1H, J=7.7 Hz), 7.83-7.86 (m, 2H), 9.89 (s, 1H). By the method of Example 316 the following compounds were prepared: a) 3-Formyl-5,7-difluoro-1H-indole: 1H NMR (300 MHz, CD3COCD3) 6.98-7.06 (m, 1H), 7.71-7.75 (m, 1H), 8.35 (s, 1H), 10.04 (s, 1H);

Provenance & Evidence