4-Bromo-2-nitrophenylacetic Acid → 6-bromo-2,3-dihydro-1H-indol-2-one

Participants

Reaction Steps

Zinc dust (8.5 g, 0.13 mol) was added slowly to a solution of 4-bromo-2-nitrophenylacetic acid (8.4 g, 0.03 mol) in 50% sulfuric acid (200 mL) and absolute ethanol (300 mL) at 90° C. over 0.75 h. The mixture was heated at this temperature for 2 h with stirring. The excess ethanol was removed by evaporation in vacuo and the mixture was filtered. The filtrate was extracted with diethyl ether. The combined organic portions were washed with saturated sodium bicarbonate, saturated sodium chloride, filtered with Whatman 1 PS Phase Separator paper and evaporated in vacuo to give 3.8 g (56%) a pale peach solid. 1H-NMR (DMSO-d6): δ10.57 (brs, 1H), 7.14 (m, 2H), 6.98 (s, 1H), 3.47 (s, 2H).

Provenance & Evidence