2,2,2-Trifluoroethanol → 2,3-Dimethyl-4-(2,2,2-trifluoroethoxy)pyridine 1-oxide

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Reaction Conditions

Reaction Steps

13.5 ml of 2,2,2-trifluoroethanol were added to the solution of 2,3-dimethyl-4-nitropyridine N-oxide (60 ml, 0.080 mole) obtained in the previous step. Then methylene chloride was distilled off. The resulting concentrated solution was added to a solution of 14.85 g (0.133 mole) potassium tert-butoxide in 54 ml of 2,2,2-trifluoroethanol and 0.034 g of palladium(II) chloride. The reaction mixture was heated to 83-88° C. for 6-8 hours. After cooling to 30° C., potassium nitrite was filtered off, following by distillation of 2,2,2-trifluoroethanol. To this residue 17 ml of a saturated solution of sodium chloride were added and the pH was adjusted by the addition of conc. hydrochloric acid to 6.6. The product was extracted with methylene chloride and 100 ml of a saturated solution of sodium chloride. The organic phases were dried with sodium sulphate and concentrated to a volume of 40 ml. The yield was 95-97%, determined by HPLC.

Provenance & Evidence