(R)—N-Ethyl-N-(7-fluoro-6-(3-(1-phenylethyl)ureido)-1H-pyrazolo[4,3-c]pyridin-3-yl)acetamide (27 mg, 0.070 mmol) was dissolved in THF (3 mL), charged with HCl (300 μL, 3.65 mmol), and heated to 60° C. for 4 h. The solvents were removed in vacuo and the residue was taken up in DMF and purified by mass-triggered reverse phase HPLC. Fractions containing pure compound were filtered through a PS-HCO3 cartridge and the filtrate was concentrated in vacuo to give (R)-1-(3-(ethylamino)-7-fluoro-1H-pyrazolo[4,3-c]pyridin-6-yl)-3-(1-phenylethyl)urea. MS ESI calc'd. for C17H19FN6O [M+1]+ 343. found 343. 1H NMR (500 MHz, DMSO-d6) δ 12.15 (s, 1H), 8.67 (s, 1H), 8.90 (br s, 1H), 8.49 (s, 1H), 7.39-7.27 (m, 4H), 7.26-7.18 (m, 1H), 4.90 (t, J=7.2 Hz, 1H), 3.25 (m, 2H), 1.42 (d, J=6.9 Hz, 3H), 1.20 (t, J=7.2 Hz, 3H).
