n-Butylithum (1.34M, 3.0 mL, 4 mmol) was added slowly to a mixture of 1H-benzo[d]imidazol-1-ylmethanol (296 mg, 2.0 mmol) in THF (9.0 mL) at −78° C. The reaction mixture was allowed to warm up to −20° C. and kept at −20° C. for 30 minutes then cooled back to −78° C. cis-4-{4-amino-1-[4-(4-methylpiperazino)cyclohexyl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}benzaldehyde (420 mg, 1 mmol) in THF (5 mL) was added slowly. After 20 minutes, the dry ice bath was removed and the reaction mixture was stirred at room temperature overnight. Saturated ammonium chloride solution was added followed by ether. The layers were separated and the aqueous layer was neutralized with sodium hydroxide (1.0N) and extracted with dichloromethane. The organic layer was washed with brine, dried over MgSO4, filtered and evaporated. The residue was first purified by flash column chromatography using dichloromethane/methanol (95:5 to 85:15) as mobile phase then by reverse phase preparative HPLC (Rainin HPLC, Column: Thermoquest, hyperprep HS C18, 8 um, 250×21.2 mm. Eluents: 5% B/A to 100% B/A in 25 min. (B: acetonitrile, A: 50 mM ammonia acetate buffer, pH 4.5), 21 mL/min.) to give cis-(4-{4-amino-1-[4-(4-methylpiperazino)cyclohexyl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}phenyl)(1H-benzo[d]imidazol-2-yl)methanol (2 mg, 0.4%). 1H NMR (CDCl3) δ 1.68 (m, 2H), 1.81 (m, 2H), 2.01 (m, 2H), 2.13 (m, 2H), 2.33 (s, 3H), 2.42 (m, 2H), 2.64 (m, 7H), 4.68 (bs, 3H), 4.93 (m, 1H), 5.77 (bs, 2H), 6.06 (s, 1H), 7.20 (m, 2H), 7.52 (m, 2H), 7.58 (m, 4H), 8.32 (s, 1H). LCMS (Thermoquest AQA single Quad MS, Finnigan HPLC-Column: Genesis, C18, 3 um, 33×4.6 mm. Eluents: 30% B/A to 95% B/A in 4.5 min. (B: acetonitrile, A: 50 mM ammonia acetate buffer, pH 4.5), 0.8 mL/min.): MH+=538.3, Rt=3.80 min.
