Dimethyl Sulfoxide → 6-Methoxy-4-(trifluoromethyl)-3-pyridinecarboxaldehyde

Participants

Reaction Steps

To a cooled (−78° C.) solution of DMSO (0.15 mL, 2.13 mmol) in dichloromethane (2 mL) was added oxalyl chloride (0.14 mL, 1.60 mmol), and the mixture was stirred for 10 minutes. 6-Methoxy-4-trifluoromethyl-3-pyridinemethanol (220 mg, 1.06 mmol) in dichloromethane (4 mL) was added to the reaction mixture. After stirring at −40° C. for 50 minutes, the mixture was treated with triethylamine (0.44 mL, 3.16 mmol), stirred for 90 minutes while warming to room temperature, and quenched with water. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to give 6-methoxy-4-trifluoromethyl-3-pyridinecarboxaldehyde (162 mg, 74.4%) as a solid. The crude product was used directly in the following Swern oxidation.

Provenance & Evidence