Lithium Hydroxide → 6-(4-Bromo-2-chloro-phenylamino)-7-fluoro-3-(tetrahydro-pyran-2-ylmethyl)-3H-benzoimidazole-5-carboxylic acid

Beteiligte Stoffe

Reaktionsschritte

6-(4-Bromo-2-chloro-phenylamino)-7-fluoro-3-(tetrahydro-pyran-2-ylmethyl)-3H-benzoimidazole-5-carboxylic acid methyl ester 11q is suspended in 4:1 tetrahydrofuran/water (2.5 mL) and aqueous 1 M LiOH is added (2.5 mL). After stirring at room temperature for 16 hours, the reaction mixture is homogeneous and the reaction is complete. The reaction mixture is cooled to 0° C., diluted with water and aqueous 2 M HCl is added dropwise until the pH of the solution is 1-2, at which time it turns to a suspension. The reaction mixture is poured into a separatory funnel and diluted with ethyl acetate/tetrahydrofuran and water and the layers separated. The aqueous layer is extracted with ethyl acetate. The combined organic layers are washed with brine, dried (Na2SO4) and concentrated under reduced pressure to yield 0.11 g (100%) of the pure desired product as a white solid. MS ESI (+) m/z 482, 484 (M+, Br pattern) detected.

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