Methanol → 1-[5-(2-fluoro-6-methylpyridin-3-yl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methylmethanamine fumarate

tert-Butyl {[5-(2-fluoro-6-methylpyridin-3-yl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]methyl}methylcarbamate (400 mg) was dissolved in methanol (20 mL), 4 mol/L hydrogen chloride-ethyl acetate solution (2 mL) was added, and the mixture was stirred at 60° C. for 10 min. The reaction mixture was concentrated under reduced pressure, saturated aqueous sodium hydrogen carbonate solution was added, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was crystallized from a mixed solution of fumaric acid (101 mg), methanol (3 mL) and ethyl acetate (12 mL) to give the title compound as colorless crystals (yield 264 mg, 64%).