Potassium Carbonate → phenyl 3-(2-ethoxypropan-2-yl)-1-phenyl-1H-pyrazol-5-ylcarbamate

Using the procedure described in Example 161C, 3-(2-ethoxypropan-2-yl)-1-phenyl-1H-pyrazol-5-amine (0.429 g, 1.75 mmol) and phenyl chloroformate (0.329 g, 2.1 mmol) were reacted in the presence of K2CO3 (0.415 g, 3 mmol) in THF (15 mL), and purified by silica gel chromatography with 15-35% EtOAc/hexane as eluants to afford phenyl 3-(2-ethoxypropan-2-yl)-1-phenyl-1H-pyrazol-5-ylcarbamate as solid (0.594 g, 93%). 1H NMR (300 MHz, CDCl3) δ 7.53 (m, 5H), 7.41-7.48 (m, 4H), 7.14-7.38 (m, 2H), 6.6 (s, 1H), 3.37 (q, 2H), 1.59 (s, 6H), 1.14 (t, 3H); LC-MS (ESI) m/z 320 (M-OEt)+.