Reaction Steps
A solution of 3-(4-amino-3-methoxyphenyl)-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-4-amine (0.500 g, 1.15 mmol) in pyridine (8 mL) at −5° C. was treated with a solution of 1H-2-indolecarbonyl chloride (0.413 g, 2.3 mmol) in dichloromethane (1 mL). The reaction mixture stirred for 20 min at −5° C. The dry ice/acetone bath was removed and the reaction mixture stirred for 18 h under nitrogen atmosphere. 1H-2-indolecarbonyl chloride (0.207 g, 1.15 mmol) was added and was stirred for an additional 2 h. Sodium hydroxide (1 N) solution (10 mL) was added and was stirred for 30 min. Organic solvent was removed under reduced pressure, and dichloromethane (25 mL) was added. The layers were partitioned, and the aqueous layer was extracted with dichloromethane. The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered, and reduced under pressure to give crude N1-(4-{4-amino-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxyphenyl))-1H-2-indolecarboxamide. N1-(4-{4-amino-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxyphenyl))-1H-2-indolecarboxamide was purified by flash chromatography on silica gel using 15% (methanol with 2% ammonium hydroxide) in dichloromethane to still give a crude product. A second column using a gradient of 10% (methanol with 2% ammonium hydroxide) to 50% (methanol with 2% ammonium hydroxide) gave 0.139 g (21%) pure N1-(4-{4-amino-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxyphenyl))-1H-2-indolecarboxamide. N1-(4-{4-amino-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxyphenyl))-1H-2-indolecarboxamide (0.139 g, 0.24 mmol) in warmed ethyl acetate was treated with a warmed solution of maleic acid (0.083 g, 0.719 mmol) in ethyl acetate. The precipitate formed was filtered under nitrogen to give 0.166 g of N1-(4-{4-amino-1-[1-(1-methylpiperidin-4-yl)piperidin-4-yl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxyphenyl))-1H-2-indolecarboxamide di-maleate. 1H NMR (DMSO-d6, 400 MHz) δ 11.83 (s, 1H), 9.442 (s, 1H), 8.283 (s, 1H), 8.154-8.134 (d, 1H, J=8.12 Hz), 7.694-7.674 (d, 1H, J=8.04 Hz), 7.498-7.477 (d, 1H, J=8.20 Hz), 7.407-7.402 (m, 1H), 7.352-7.325 (m, 2H), 7.267-7.229 (m, 1H), 7.112-7.074 (m, 1H), 6.078 (s, 4H), 5.10-5.00 (m, 1H), 3.974 (s, 3H), 3.525 (m, 4H), 3.178 (m, 2H), 2.975 (m, 2H), 2.771 (s, 3H), 2.457 (s, 3H), 2.208 (m, 4H), 1.909 (m, 2H); HPLC Perkin Elmer Pecosphere C18, 3 μM, 33×4.6, 3.5 ml/min 100-100% 50 mM ammonium acetate to acetonitrile in 4.5 minutes, C36H44N6O3 (581.2), 95%. LCMS (Perkin Elmer, Pecosphere C18 column, 3 um particle size, 33×4.6 mm; 100% 50 mM ammonium Acetate in Water to 100% Acetonitrile over 5 min, 3.0 to 3.5 mil/min) Rt 2.67 min (100%).
