Hydrochloric Acid → Bilastine

Participants

Reaction Steps

In a reaction vessel, 2-[1-(2-{4-[1-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-1-methyl-ethyl]-phenyl}-ethyl)-piperidin-4-yl]-1-(2-ethoxy-ethyl)-1H-benzoimidazole (4.4 g) prepared in the Example 18 and hydrochloric acid aqueous solution (50 mL) were introduced, and the mixture was stirred with reflux. After the reaction was completed, sodium hydroxide solution was added to control the pH to 7. Ethylacetate (50 mL) was added to separate a layer, and the organic layer was condensed under reduced pressure. And, butanol (9 mL) was added and dissolved by heating. And then, it was cooled to precipitate crystals, and the crystals were filtered under reduced pressure to obtain 2-[4-(2-{4-[1-(2-ethoxy-ethyl)-1H-benzoimidazol-2-yl]-piperidin-1-yl}-ethyl)-phenyl]-2-methyl-propionic acid (3.43 g, yield 87%, HPLC purity 99% or more).

Provenance & Evidence