5-Bromoisatin → 5-Bromo-3-hydroxy-3-prop-1-ynyl-1,3-dihydroindol-2-one

Participants

Reaction Steps

To a solution of 5-bromoisatin (2.5 g, 11 mmol) in dry THF (100 cm3) at −10° C. under a nitrogen atmosphere was added 1-propynylmagnesium bromide (0.5 M in THF, 47 cm3, 23.5 mmol). After 1 h, the mixture was poured into saturated ammonium chloride and extracted with EtOAc (×3), washed with brine, dried (MgSO4) and evaporated to afford 5-bromo-3-hydroxy-3-prop-1-ynyl-1,3-dihydroindol-2-one (2.83 g, 10.6 mmol, 97%) which was used without further purification: (CDCl3) δ 1.83 (s, 3H), 6.79 (d, 1H, J=8.0 Hz), 6.90 (s, 1H), 7.41–7.44 (m, 2H), 10.59 (s, 1H); MS ((−) ESI) m/z 264 (M−H)−.

Provenance & Evidence