[6-(4-Bromo-2-chloro-phenylamino)-7-fluoro-3H-benzoimidazol-5-yl]-methanol → 6-(4-Bromo-2-chloro-phenylamino)-7-fluoro-3H-benzoimidazole-5-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

[6-(4-Bromo-2-chloro-phenylamino)-7-fluoro-3H-benzoimidazol-5-yl]-methanol 10e (0.96 g, 2.58 mmol) is dissolved in tetrahydrofuran/acetone (1:1, 15 mL), and MnO2 (2.24 g, 25.8 mmol) is added. The reaction mixture is stirred at 50° C. for 10 hours under N2. The reaction mixture is filtered through silica gel and eluted with methylene chloride/methanol (10:1, 1 L). The filtrate is concentrated under reduced pressure to a small volume and then filtered through an Acrodisc syringe filter to remove small amounts of MnO2 that passed through the silica gel. The filtrate is concentrated under reduced pressure and the residue is purified by flash column chromatography (eluting with 20:1 methylene chloride:methanol) to yield 0.81 g (85%) of the pure desired product as a bright yellow solid. MS ESI (+) m/z 368, 370 (M+, Br pattern) detected.

Provenance & Evidence