2-(4-Bromo-2,6-dimethylphenyl)cyclopent-4-ene-1,3-dione → 2-(4-Bromo-2,6-dimethylphenyl)cyclopentane-1,3-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(4-bromo-2,6-dimethylphenyl)cyclopent-4-ene-1,3-dione (described in WO 2010/089210) (50 g, 0.18 mol) in acetic acid (2000 ml) at 25-30°C. is added zinc powder (82.3 g, 1.26 mol). The resulting suspension is heated to 90°C. for 2 hours, followed by cooling to room temperature then filtration through a bed of diatomaceous earth. The residue is washed with methanol (100 ml×2) and the solution is concentrated in vacuo. Distilled water is added and the crude product is extracted with ethyl acetate (500 ml×3). Organic fractions are combined then washed with distilled water, brine, then dried over sodium sulfate, filtered and the filtrate concentrated in vacuo to afford 2-(4-bromo-2,6-dimethylphenyl)cyclopentane-1,3-dione. This material is used directly in the next step without further purification.

Provenance & Evidence