Ethyl Acetate → 2,4-Dimethyl-5-nitropyridine

Participants

Reaction Steps

To a stirred suspension of 2-chloro-4-methyl-5-nitropyridine (9.419 g, 54.6 mmol) in dioxane (110 mL) was added tetrakis(triphenyl phosphine) palladium (6.330 g, 5.46 mmol) and the mixture stirred for 15 min prior to the addition of trimethyl boroxine (7.68 mL, 54.6 mmol) and potassium carbonate (22.64 g, 164.0 mmol). The reaction mixture was heated under reflux for 6 h then allowed to cool to rt over 16 h. Ethyl acetate (200 mL) was added and the mixture stirred vigorously for 1 h. The mixture was filtered through celite, washing through with ethyl acetate/THF (1:1, v/v). Brine (100 mL) was added and attempted separation of layers resulted in a thick emulsion. After removal of all volatiles, ethyl acetate (300 mL) was added and the mixture filtered, giving rise to a biphasic mixture. The layers were separated and the aqueous phase was extracted with ethyl acetate (3×100 mL). The combined organics were washed with brine (100 mL), dried (MgSO4), filtered and concentrated in vacuo. The resulting oil was dissolved in dichloromethane then purified via flash column chromatography (SiO2, ethyl acetate/isohexane, 3:7, v/v) to give the title compound as an orange oil. δH (CDCl3): 2.59 (3H, s), 2.60 (3H, s), 7.12 (1H, s), 9.07 (1H, s).

Provenance & Evidence