Cesium carbonate → 2-(1,3-Benzodioxol-5-yloxy)pyridine-3-carboxylic acid

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Reaction Steps

2-Chloro-nicotinic acid ethyl ester (10 g), benzo[1,3]dioxol-5-ol (sesamol, 8.2 g), and cesium carbonate (21 g) were mixed in anhydrous dioxane (40 mL) and the resulting slurry heated to reflux for 16 h. In a separate flask, lithium hydroxide (12.9 g) was dissolved in water (80 mL) with warming and then added to the refluxing mixture, which was heated for an additional 4 h. The mixture was cooled to ambient temperature and concentrated in vacuo to remove the dioxane. Concentrated hydrochloric acid was added dropwise until the pH=3. The acidified solution was then extracted with ethyl acetate (7×100 mL) to yield crude product, which was recrystallized from ethyl acetate to yield the purified title compound (10.8 g).

Provenance & Evidence