Dimethyl Sulfoxide → 6-Phenoxypyridine-2-carbaldehyde

Participants

Reaction Steps

A solution containing 21.0 ml of dry DMSO in 150 ml of dry CH2Cl2 under an atmosphere of nitrogen was cooled to -75° (internal). To this reaction mixture was then added 31.0 g of trifluoroactic anhydride at such a rate to maintain the temperature below -60° (internal). After the addition was complete the reaction mixture was stirred at -75° for 20 min. To the resulting mixture was added a solution containing 29.25 g of 6-phenoxypyridine-2-pyridinemethanol in 150 ml CH2Cl2. During this addition the internal temperature was not allowed to rise above -60° C. After stirring this reaction mixture for 1 hr. at -75° C., 90 ml of triethylamine was added. The cooling bath was removed and the reaction mixture was allowed to warm to room temperature. The reaction mixture was diluted with 1 L of ether and washed four times with H2O. After drying over anhydrous Na 2 SO4, removal of the solvents afforded 29.31 g of dark oil. This material was treated with decolorizing carbon and recrystallized from hexane-ethyl acetate to afford 21.50 g of the desired crystalline aldehyde.

Provenance & Evidence