Hydrogen Bromide → 6-hydroxy-1,3,3-trimethyl-2,3-dihydro-1H-indol-2-one

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Reaction Steps

To a solution of 6-methoxy-1,3,3-trimethyl-1,3-dihydro-indol-2-one (601 mg, 2.93 mmol) in acetic acid (880 μL) is added hydrobromic acid (48% in H2O) (8.8 mL). The resulting solution is heated to reflux (105°-110° C.), stirred 2 hrs, then cooled to room temp and concentrated under reduced pressure. The residue is dissolved in EtOAc and the organic layer washed with water, brine, dried over MgSO4 and concentrated. The residue is purified by triturating with a small volume of ether to give 495 mg of title compound as an off white solid. MS (ESI) 192 (M+H)+.

Provenance & Evidence