Trifluoroacetic acid → 5-(3-Chloropropyl)-3,3-dimethyl-1,3-dihydro-indol-2-one

Participants

Reaction Conditions

Reaction Steps

Under nitrogen atmosphere, add 5-(3-chloropropyl)-3,3-diethyl-1,3-dihydro-indol-2-one (3.08 g, 12.24 mmol) to trifluoroacetic acid (9.4 mL, 122.4 mmol). Cool the resulting suspension to 0° C. and then add triethylsilane (4.5 mL, 28.2 mmol) dropwise over 2 min. Heat at 45° C. for 30 min then stir at ambient temperature overnight. Pour the reaction mixture onto ice/water (100 mL) and extract with EtOAc (2×100 mL). Dry the combined extracts over MgSO4, filter and concentrate in vacuo. Purify the crude mixture by chromatography on silica gel eluting with hexane/EtOAc (1:0 to 4:1 gradient), to give the title compound as a yellow-orange solid (2.12 g, 73%).

Provenance & Evidence