Hydrochloric Acid → Methyl 2-(2,4-difluorophenyl)isonicotinate hydrochloride

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Reaction Conditions

Reaction Steps

Methyl 2-chloroisonicotinate (3 g, 17.48 mmol), 2,4-difluorophenylboronic acid (4.14 g, 26.23 mmol), potassium carbonate (1.812 g, 13.11 mmol) and PdCl2 (dppf) (0.380 g, 0.52 mmol) were mixed in methanol (30 mL) in two separate 20 mL microwave vials. The vials were capped and heated at 100° C. for 10 min in a single node microwave reactor. Water and DCM were added and the phases were separated. The water phase (pH 9) was extracted with DCM and the combined organic phase washed with brine, passed through a phase separator and evaporated to yield a brown solid. The solid was dissolved in MTBE and stirred for 15 minutes, then filtered. The orange MTBE layer was treated with hydrogen chloride (4 M in dioxane, 4.37 mL, 17.48 mmol) and stirred for 1 h at room temperature. The formed solid was collected by filtration. Methyl 2-(2,4-difluorophenyl)isonicotinate hydrochloride (4.0 g, 80%) was isolated as a slightly orange solid. MS m/z 250 (M+H)+

Provenance & Evidence