Oxalyl chloride → 1-(4-Methylphenyl)cyclopentane carboxylic acid t butyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1-(4-methylphenyl)cyclopentane carboxylic acid (3.00 g, 14.7 mmol) in dichloromethane (50 mL) at 0° C. was added oxalyl chloride (1.54 mL, 17.4 mmol) and DMF (2 drops). The mixture was stirred at 0° C. for 1 hour, and at rt for 2 hours. The solution was concentrated, diluted with THF (40 mL), and cooled to 0° C. Potassium t butoxide (1.80 g, 16.2 mmol) in THF (20 mL) was slowly added, and the mixture was stirred overnight at rt. Additional potassium t butoxide (0.660 g, 5.88 mmol) was added. After 20 minutes the solution was concentrated to dryness, and taken up in ethyl acetate. The organic phase was washed with 10% citric acid, saturated NaHCO3 and brine, dried (MgSO4), and concentrated. Flash column chromatography (10% ethyl acetate/hexane) gave 1-(4-methylphenyl)cyclopentane carboxylic acid t butyl ester (3.27 g, 87%).

Provenance & Evidence