Nitrosobenzene → 5-(3-Amino-benzoyl)-1,3-dihydro-indol-2-one

Participants

Reaction Steps

5-(3-Nitro-benzoyl)-1,3-dihydro-indol-2-one (2.0 g, 7.09 mmol) was dissolved in MeOH (600 mL). 10% Pd/C (0.20 g) was added to the flask and then placed under vacuum to remove any O2(g). The reaction mixture was kept under reduced pressure for ˜5 min and was then charged with H2(g) at atmospheric pressure. This evacuation/H2(g) fill procedure was repeated twice. The reaction mixture was stirred for 2 h at which point the starting material had been completely consumed. As the desired ketone product was prone to over-reduction to the alcohol, stopping the reaction immediately upon complete consumption of the starting material limited the amount over-reduction that occurred. The reaction mixture was filtered over celite and the filtrate was concentrated in vacuo resulting in a solid that contained the desired keto-aniline product plus ˜5% of the overreduced alcohol-aniline. Flash silica gel chromatography (5% MeOH/CHCl3) of the crude solid provided pure 5-(3-Amino-benzoyl)-1,3-dihydro-indol-2-one in 72% (0.957 g, 3.80 mmol) yield.

Provenance & Evidence