Sodium Hydroxide → 4-Bromo-6-fluoro-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a solution of crude[(E)-2-(2-bromo-4-fluoro-6-nitrophenyl)ethenyl]dimethylamine (D15) (6.07 g, 21.0 mmol) in acetic acid (200 mL) and water (50.0 mL) at 75° C. was added zinc powder (15.11 g, 231 mmol) portionwise over 1 hour. The mixture was heated to 85° C. and stirred for 4 hours. After cooling to room temperature, the reaction mixture was neutralised by the addition of 50% aqueous sodium hydroxide solution. The product was extracted into diethyl ether. After separation of the layers, the aqueous phase was re-extracted with diethyl ether. The combined organic layers were dried over magnesium sulphate, filtered and concentrated. The product was partially purified by silica gel chromatography eluting with 5-30% ethyl acetate in hexane. Purer fractions were combined to give the title compound (D16), (580 mg).

Provenance & Evidence