Swern Oxidation

The Swern oxidation, named after Daniel Swern, is a chemical reaction whereby a primary or secondary alcohol is oxidized to an aldehyde or ketone using oxalyl chloride, dimethyl sulfoxide (DMSO) and an organic base, such as triethylamine. The reaction is known for its mild character and wide tolerance of functional groups.

The by-products are dimethyl sulfide (Me₂S), carbon monoxide (CO), carbon dioxide (CO₂) and — when triethylamine is used as base — triethylammonium chloride (Et₃NHCl). Two of the by-products, dimethyl sulfide and carbon monoxide, are very toxic volatile compounds, so the reaction and the work-up needs to be performed in a fume hood. Dimethyl sulfide is a volatile liquid (B.P. 37 °C) with an unpleasant odour.

Several reviews have been published.