Hydrochloric Acid → 6-(1-((6-Cyclopropyl-2,4'-difluoro-3-isopropoxybiphenyl-4-yl)methyl)piperidin-4-yl)-2-ethyl-5-oxo-5,6,7,8-tetrahydro-1,6-naphthyridine-3-carboxylic acid

Participants

Reaction Steps

2M aqueous sodium hydroxide solution (20 mL) was added to a solution of methyl 6-(1-((6-cyclopropyl-2,4′-difluoro-3-isopropoxybiphenyl-4-yl)methyl)piperidin-4-yl)-2-ethyl-5-oxo-5,6,7,8-tetrahydro-1,6-naphthyridine-3-carboxylate (8.03 g) in methanol (25 mL) at 70° C. The mixture was stirred at the same temperature under nitrogen atmosphere for 2 hours. The mixture was neutralized with 1M hydrochloric acid at room temperature and added to water (100 mL). The mixture was stirred at 70° C. for 30 minutes and at room temperature for 2 hours to give colorless crystals. After filtration, the crystals were dissolved in ethanol. The solution was filtrated and the filtrate was concentrated in vacuo to give a colorless solid. The solid was recrystallized from ethanol-water (45 mL-130 mL) to give the title compound (7.26 g).

Provenance & Evidence