Example 22
To a stirred solution of 3-(3,4-dimethoxyphenyl)-5-(4-piperidyl)-1,2,4-oxadiazole (150 mg, 518 μmol) in N,N-dimethylformamide (2 mL) was added (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (196 mg, 518 μmol) and N-ethyl-N-(propan-2-yl)propan-2-amine (201 mg, 1.56 mmol, 271 μL) and 2-[benzoyl(methyl)amino]acetic acid (105 mg, 544 μmol). The mixture was stirred at 20° C. for 5 h, then cooled and purified directly by prep-HPLC (column: Luna C8 100×30 5 μm; mobile phase: [water (10 mM ammonium carbonate)-acetonitrile]; B%: 30%-60%, 12 min) to give N-[2-[4-[3-(3,4-dimethoxyphenyl) -1,2,4-oxadiazol-5-yl]-1-piperidyl]-2-oxo-ethyl]-N-methyl-benzamide (133 mg, 282 μmol, 54%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ=7.59 (dd, J=1.8, 8.4 Hz, 1H), 7.49-7.32 (m, 5H), 7.27 (br d, J=6.8 Hz, 1H), 7.16-7.08 (m, 1H), 4.44-4.24 (m, 2H), 4.21-4.03 (m, 1H), 4.02-3.88 (m, 1H), 3.88-3.74 (m, 6H), 3.56 (br d, J=13.7 Hz, 1H), 3.48-3.33 (m, 1H), 3.11-2.77 (m, 5H), 2.20-1.99 (m, 2H), 1.86 (br t, J=12.6 Hz, 1H), 1.74-1.48 (m, 2H), 1.43-1.26 (m, 1H); LCMS (ESI) m/z: [M+H]+=465.3.
