Using the procedure of method 1A, triethylamine (4.0 ml, 28.0 mmol) was added to a mixture of 4-[[(3-chloro-4-methoxyphenyl)methyl]amino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid (2.0 g, 5.6 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (EDAC.HCl, 1.6 g, 8.4 mmol), and 1-hydroxybenzotriazole (1.1 g, 8.4 mmol) in anhydrous THF (50 ml). The resulting solution was stirred at rt for 10 min. To the resulting reaction solution was then added 4-aminomethylpyridine (0.72 g, 6.7 mmol) and this solution was stirred at rt for 24 h. The resulting reaction solution was concentrated via evaporation under reduced pressure, and the residual solid was resuspended in EtOAc (250 mL). This EtOAc suspension was washed with H2O (200 ml), NaOH (0.1 N, 2×200 ml), potassium phosphate buffer (50 mM, pH 7, 2×200 ml) and H2O (200 mL). The organic layer was then dried over anhydrous Na2SO4 and concentrated via evaporation under reduced pressure until a solid began to precipitate. This mixture was allowed to stand at rt, and the precipitated solid was collected and washed thoroughly with Et2O and once with 50% Et2O-EtOAc to afford a white solid (2.2 g, 90%): mp: 209-210.5 C; LRMS (m/z) 450; 13C NMR (CDCl3): δ 171.8, 156.4, 153.7, 153.1, 151.7, 150.8, 150.5, 135.7, 132.0, 130.5, 128.3, 124.5, 124.3, 114.2, 105.6, 104.4, 57.4, 49.8, 43.7, 43.6, 15.9. Anal. Calc'd for C23H23C1N6O2: C, 61.26; H, 5.14; N, 18.64; Cl, 7.86. Found: C, 61.03; H, 5.22; N, 18.66; Cl, 8.02.
