To a suspension of 2-((R)-3-amino-piperidin-1-yl)-5-(pyridin-2-ylamino)-thiazole-4-carboxylic acid amide (prepared as described in example 4) (5.6 mg, 171 μmol) in tetrahydrofuran (1 mL) was added N,N-dimethylformamide (0.5 mL) to form a clear solution. Diisopropylethylamine (59.9 μL, 343 μmol) was added followed by methanesulfonyl chloride (20 μL, 257 μmol) and the mixture left to stir overnight at ambient temperature under argon. The reaction mixture was quenched by the addition of saturated aqueous ammonium chloride solution (2 mL), poured into water (5 mL) and extracted with ethyl acetate (5×2 mL), the combined organic extracts were washed with brine (2×2 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by reverse phase chromatography using a C-18 column gradient eluted from 10% acetonitrile in water to 100% acetonitrile. The product containing fractions were combined and concentrated in vacuo. The residue was lyophilized from water/ethanol to give (R)-2-(3-(methylsulfonamido)piperidin-1-yl)-5-(pyridin-2-ylamino)thiazole-4-carboxamide as an off-white lyophilized powder (41 mg, 60%).
