hydroxylamine-O-sulfonic acid → 1-Amino-3-(4-fluorophenyl)-5-methyl-1H-indole

Participants

Reaction Steps

Potassium tert-butoxid (7.5 g) was added to a solution of 3-(4-fluorophenyl)-5-methyl-1H-indole 1c (15 g) in DMF during 15 min at 0°-5° C. Then a suspension of potassium hydroxylamine-O-sulphonate in DMF (prepared by addition of potassium tert-butoxid (7.5 g) to a suspension of hydroxylamine-O-sulphonic acid (7.6 g) in DMF (100 ml) during 0.5 h at 0°-5° C.) was added slowly at 0°-5° C. After reaction at 0° C. for 1 h the mixture was poured into ice, and extracted with diethyl ether (2×250 ml). The combined organic phases were washed with brine (3×250 ml) and dried (Na2SO4). Evaporation of the solvents afforded the title compound which was purified by column chromatography on silica gel (eluted with ethyl acetate/heptane 1:3) and crystallized from diethylether. Yield: 4.3 g, mp 116°-120° C.

Provenance & Evidence