Hydrochloric Acid → 5-Chloro-6-(1-isopropyl-piperidin-4-yloxy)-3-methyl-benzofuran-2-carboxylic acid

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Reaction Steps

The above prepared 5-chloro-6-(1-isopropyl-piperidin-4-yloxy)-3-methyl-benzofuran-2-carboxylic acid ethyl ester (0.897 g, 2.36 mmol) was dissolved in 4.8 mL of THF/ethanol=1/1 and treated with 1.18 mL of aq. NaOH (3M, 1.5 eq.). The mixture was stirred for 3 h at ambient temperature and was then neutralized by adding 1.77 mL of 2M HCl (1.5 eq.). Careful evaporation of all solvents and drying afforded finally 1.161 g of the title compound as off-white solid, contaminated with innocuous inorganic salts.

Provenance & Evidence