4-Hydroxybenzaldehyde → N-[3-[5-chloro-2-(difluoromethoxy)phenyl]-1-(2-[[(4-hydroxyphenyl)methyl]amino]ethyl)-1H-pyrazol-4-yl]pyrazolo[1,5-a]pyrimidine-3-carboxamide

Participants

Reaction Steps

A solution of 4-hydroxybenzaldehyde (55 mg, 0.45 mmol) and N-[1-(2-aminoethyl)-3-[5-chloro-2-(difluoromethoxy)phenyl]-1H-pyrazol-4-yl]pyrazolo[1,5-a]pyrimidine-3-carboxamide (100 mg, 0.22 mmol) in THF (10 mL) was stirred at room temperature for 2 h and then NaBH3CN (28 mg, 0.45 mmol) was added. The resulting solution was stirred at room temperature overnight. The reaction was then quenched by the addition of 0.1 mL of water. The resulting mixture was concentrated under vacuum. The residue was passed through a short pad of silica gel eluting with 3% MeOH in DCM. The crude product was purified by Prep-HPLC with the following conditions (Prep-HPLC-005): Column, XBridge Prep C18 OBD Column, 5 um, 19*150 mm; mobile phase, water with 0.05% FA and MeCN (34.0% MeCN up to 38.0% in 10 min, up to 95.0% in 1 min, hold 95.0% in 1 min, down to 34.0% in 2 min); Detector, UV 254/220 nm. This resulted in 31.4 mg (23%) of the formic acid salt of N-[3-[5-chloro-2-(difluoromethoxy)phenyl]-1-(2-[[(4-hydroxyphenyl)methyl]amino]ethyl)-1H-pyrazol-4-yl]pyrazolo[1,5-a]pyrimidine-3-carboxamide as an off-white solid. LCMS (Method 20) [M+H]+=554.2, RT=1.58 min. 1H NMR (400 MHz, DMSO-d6) δ: (ppm) 9.74 (s, 1H), 9.34 (dd, 1H, J=1.6, 7.2 Hz), 8.69-8.67 (m, 2H), 8.37 (s, 1H), 7.62 (dd, 1H, J=2.8, 8.8 Hz), 7.60 (d, 1H, J=2.4 Hz), 7.44 (d, 1H, J=8.4 Hz), 7.28 (dd, 1H, J=4.4, 7.2 Hz), 7.10 (d, 2H, J=8.4 Hz), 7.06 (t, 1H, J=73.2 Hz), 6.68 (d, 2H, J=8.4 Hz), 4.25 (t, 2H, J=6.4 Hz), 3.63 (s, 2H), 2.95 (t, 2H, J=6.0 Hz).

Provenance & Evidence