Hydrochloric Acid → HCID 67975084, compound

Participants

Reaction Steps

To a solution of 5-bromo-3-chloro-2,4-dimethylpyridine 1-oxide (373 mg; 1.5772 mmol) in dichloromethane (10 mL; 156.0 mmol) was added trifluoroacetic anhydride (0.70 mL; 5.0 mmol). The reaction mixture was stirred at room temperature for 20 hours. Trifluoroacetic anhydride (0.5 mL; 4 mmol) was then added and the reaction mixture stirred for an additional 4 hours at room temperature. The reaction mixture was poured into 2M aqueous potassium carbonate and extracted twice with dichloromethane. The combined dichloromethane extracts were dried over magnesium sulfate, filtered, and evaporated in vacuo. The resulting residue was dissolved in tetrahydrofuran (6 mL), and treated with sodium hydroxide (10 mol/L) in water (0.60 mL; 6.0 mmol). The mixture was stirred at room temperature for 2 hours, and then neutralized with 5M aqueous HCl (1.3 mL). The reaction mixture was poured into saturated aqueous sodium bicarbonate and extracted with dichloromethane (3×100 mL). The combined organic extracts were dried over magnesium sulfate, filtered, and concentrated. The crude product was purified via flash chromatography on silica gel (24 g silica, solvent gradient: 20-100% ethyl acetate in dichloromethane) to yield 255.6 mg (69%) of the title compound. LCMS (ESI): M+H=236.2; 1H NMR (400 MHz, CDCl3) δ 8.55 (s, 1H), 4.73 (d, J=4.8 Hz, 2H), 4.05 (s, 1H), 2.55 (s, 3H).

Provenance & Evidence