4-Bromotoluene → 2-(4-Methylphenyl)cyclohexanone

Participants

Reaction Conditions

Reaction Steps

To a solution of p-tolylbromide (17.1 g, 100 mmol) in dry THF (100 mL) was added magnesium (2.43 g, 100 mmol) and then the resulting mixture was cooled to −20° C. and (CuBr-dimethylsulfide complex (2.0 g, 10 mmol) was added and the mixture stirred at −20° C. for 10 min. Then a solution of cyclohexene oxide (10 mL, 100 mmol) in dry THF (10 mL) was added dropwise and the reaction warmed to 0° C. at which point an exothermic reaction initiates. With ice-bath cooling the temperature can be maintained below 25° C. The reaction mixture was then stirred at 0–5° C. for an additional 2 h, then quenched with ammonium chloride solution (saturated, 30 mL) and the product extracted with tert-butyl methyl ether. The combined organic extracts were then washed with water, dried over sodium sulfate, filtered and evaporated. Recrystallisation from hexane afforded the title compound (9.9 g, 52%) as white crystals. MS: m/e=190.1 (M).

Provenance & Evidence