Diisopropylethylamine → 2-(4-Chloro-5-methyl-3-oxazol-2-yl-pyrazol-1-yl)-1-[4-(4-fluoro-benzyl)-4-hydroxy-piperidin-1-yl]-ethanone

Participants

Reaction Steps

To a 20 mL vial equipped with a magnetic stirring bar was added 63 mg of 4-(4-Fluoro-benzyl)-piperidin-4-ol (0.3 mmol, 1.2 equiv.), 62 mg of (4-Chloro-5-methyl-3-oxazol-2-yl-pyrazol-1-yl)-acetic acid (0.26 mmol, 1.0 equiv), and 138 mg of benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate (0.27 mmol, 1.0 equiv). The reagents were dissolved in 0.6 mL of DMA and to the resultant solution was added 0.18 mL of DIPEA (1.0 mmol, 3.8 equiv.). The reaction solution was stirred for 14 h and then poured into 50 mL of EtOAc. The organic extracts were washed with saturated aq. NaCl (5×10 mL), 1% aq NaOH (1×10 mL), and 0.1 N HCl (1×10 mL). The organic extracts were dried over MgSO4 and concentrated in vacuo to afford a yellow oil, which was purified by preparative HPLC to afford 34 mg of 2-(4-Chloro-5-methyl-3-oxazol-2-yl-pyrazol-1-yl)-1-[4-(4-fluoro-benzyl)-4-hydroxy-piperidin-1-yl]-ethanone (30% yield): MS (ES) M+H expected=413.2, found 413.2. 1H NMR (CDCl3, 400 MHz, 23° C.) δ 7.69 (s, 1H), 7.27 (s, 1H), 7.11-7.14 (m, 2H), 6.98-7.03 (m, 2H), 5.06 (d, J=16.0 Hz, 1H), 4.93 (d, J=16.0 Hz, 1H), 4.32-4.35 (m, 1H), 3.66-3.69 (m, 1H), 3.43-3.50 (m, 1H), 2.96-3.03 (m, 1H), 2.74 (s, 2H), 2.30 (s, 3H), 1.55-1.63 (m, 4H).

Provenance & Evidence