To a solution of tert-butyl 6-(4-(3-(acetamidomethyl)pyrrolidin-1-yl)furo[3,2-d]pyrimidin-2-ylamino)-3-methyl-1H-indazole-1-carboxylate (0.57 g, 1.1 mmol, prepared using E.1 from tert-butyl 3-(aminomethyl)pyrrolidine-1-carboxylate hydrochloride [Astatech] with acetyl chloride, C, A with 2,4-dichlorofuro[3,2-d]pyrimidine [ArkPharm] and B with Example #3, Step B) in MeOH (12 mL) was added concentrated HCl (12 mL). The mixture was stirred for about 32 h at about 90° C. The mixture was cooled to rt, and a white precipitate formed that was collected by vacuum filtration and washed with water. The solid was dissolved in hot aqueous 1 M HCl and the suspension was filtered while hot. To the filtrate was added aqueous NH4OH to reach a pH˜9, and the resulting precipitate was collected to give 4-(3-(aminomethyl)pyrrolidin-1-yl)-N-(3-methyl-1H-indazol-6-yl)furo[3,2-d]pyrimidin-2-amine (0.27 g, 61%): LC/MS (Table 2, Method h) Rt=1.61 min; MS m/z: 364 (M+H)+. Syk IC50=A
