Sulfamic Acid → 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid

Participants

Reaction Steps

To a stirred suspension of 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde (500 mg, 1.18 mmol) and sulfamic acid (685 mg, 7.05 mmol) in dioxane (25 mL) and water (0.556 mL) in an ice bath was added a solution of sodium chlorite (146 mg, 1.61 mmol) and potassium dihydrogen phosphate (1.92 g, 14.1 mmol) in water (2.78 mL). The reaction mixture was stirred at room temperature for overnight. The reaction mixture was diluted with ethyl acetate and water. The organic layer was separated, washed with brine then dried (sodium sulfate), filtered and concentrated in vacuo. The crude residue was recrystallized from ethyl acetate and hexane to give 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid (467 mg, 89%) as a light yellow solid. This was used directly in the next step without further purification. LCMS, [M+H]=442.

Provenance & Evidence