Acetic Anhydride → 2-Hydroxymethyl-3-methyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine

Concentrated sulfuric acid (2 drops) was added to a solution or 2,3-dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)-pyridine-1-oxide (2.5 g) in acetic anhydride (8 ml) and the mixture was stirred at 110° C. for 2 hours and then concentrated. The residue was dissolved in methanol (30 ml), 2 N aqueous sodium hydroxide (20 ml) was added, and the mixture was stirred at room temperature for 2 hours. After concentration, water was added to the residue and the mixture was extracted with ethyl acetate. The extract was dried over magnesium sulfate, the solvent was then distilled off, and the residue was applied to a silica gel (50 g) column. Elution with chloroform-methanol (10:1) and recrystallization from isopropyl ether gave 1.6 g of 2-hydroxymethyl-3-methyl-4-(2,2,3,3,3-pentafluoropropoxy)-pyridine as a brown oil.