Dimethyl Sulfoxide → 3-{[3-Amino-5-fluoro-4-(methyloxy)-1H-indazol-1-yl]methyl}benzonitrile

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Reaction Steps

Finely ground potassium hydroxide (6.59 g, 118 mmol, 2.5 equiv.) was treated with DMSO (100 mL). To this was added 5-fluoro-4-(methyloxy)-1H-indazol-3-amine (for a preparations see Intermediate 56) (8.5 g, 47 mmol) and the mixture stirred at room temperature for 50 minutes. To the red coloured mixture was added 3-chloromethyl benzonitrile (8.9 g, 59 mmol, 1.25 equiv.) in one portion. A small exotherm of ˜5° C. was observed. The mixture was allowed to stir at room temperature for 25 minutes before pouring into water (600 mL) and extracting with chloroform (400 mL). The aqueous was re-extracted with chloroform (2×400 mL). The organic extracts were combined, washed with water (3×500 mL), dried over MgSO4, filtered and evaporated to give the crude product. This was dry loaded onto silica and chromatographed eluting with 20% petrol up to 70% EtOAc-petrol. The material came off impure so was re-chromatographed on a suction column. The impure material was loaded in DCM and eluted with DCM up to 30% EtOAc-DCM to give the title compound (8.25 g, 48%) as an off-white solid. LCMS (System A) RT=0.96 min, ES+ve m/z 297 (M+H)+.

Provenance & Evidence