To a solution of tert-butyl 4-(4-(5-acetyl-4-chloro-6-(2-(isopropylsulfonyl)phenylamino)pyrimidin-2-ylamino)-5-isopropoxy-2-methylphenyl)piperidine-1-carboxylate (81 mg, 0.12 mmol) in EtOH (2 mL) was added hydrazine dichloride (36 mg, 0.34 mmoL) and sodium acetate (47 mg, 0.57 mmol) sequentially, and the reaction mixture was heated at 80° C. overnight. The reaction was cooled to room temperature and concentrated in vacuo. The crude was dissolved in the solution of TFA (2 mL) in DCM (2 mL), and the reaction was stirred for 30 min, followed by concentration and purification by RP-HPLC to afford N6-(2-isopropoxy-5-methyl-4-(piperidin-4-yl)phenyl)-N4-(2-(isopropylsulfonyl)phenyl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine. MS (ES+): 578.3 (MH+).
