Potassium Phosphate, Tribasic → (R)-1-(3-ethoxy-1H-pyrazolo[4,3-c]pyridin-6-yl)-3-(1-(4-fluorophenyl)ethyl)urea

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 6-chloro-3-ethoxy-1H-pyrazolo[4,3-c]pyridine-1-carboxylate (77 mg, 0.259 mmol), (R)-1-(1-(4-fluorophenyl)ethyl)urea (Intermediate 15B; 60 mg, 0.329 mmol), bippyphos (15.6 mg, 0.031 mmol), Pd2(dba)3 (9.6 mg, 10.48 μmol), and tripotassium phosphate (82 mg, 0.388 mmol) were taken up in DME (1.3 mL) in a 5 mL microwave vial. The vial was evacuated and back-filled with N2 (×3) and the reaction stirred at 85° C. for 18 h. Room temperature was attained, the reaction mixture was filtered through Celite, eluting with MeOH, and the filtrate was concentrated in vacuo. The residue was dissolved in TFA (2 mL) and the solution stirred at room temperature for 3 h. The solvent was removed in vacuo, saturated NaHCO3 was added, and the products extracted into EtOAc (×2). The combined organic extracts were washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo. Purification of the residue by flash chromatography (0-100% EtOAc-DCM) gave (R)-1-(3-ethoxy-1H-pyrazolo[4,3-c]pyridin-6-yl)-3-(1-(4-fluorophenyl)ethyl)urea. MS ESI calc'd. For C17H18FN5O2 [M+1]+ 344. found 344. 1H NMR (500 MHz, DMSO-d6) δ 1H NMR (500 MHz, DMSO-d6) δ 11.94 (s, 1H), 8.91 (s, 1H), 8.53 (s, 1H), 7.76 (br s, 1H), 7.46 (s, 1H), 7.39-7.33 (m, 2H), 7.15 (t, J=8.8 Hz, 2H), 4.89-4.82 (m, 1H), 4.33 (q, J=7.0 Hz, 2H), 1.41-1.34 (m, 6H).

Provenance & Evidence