[H-].[Na+].[CH3:3][C:4]1[NH:8][N:7]=[C:6]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH:5]=1.C1(=O)O[CH2:18][CH2:17][O:16]1>CN(C=O)C>[CH3:3][C:4]1[N:8]([CH2:18][CH2:17][OH:16])[N:7]=[C:6]([C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH:5]=1Sodium hydride (2.5 g, 1.5 g NaH, 62 mmol, 1.1 equiv) was added over a period of 3 min to a solution of 5-methyl-3-phenyl-1H-pyrazole (9.00 g, 56.9 mmol, 1 equiv) in DMF (90 mL) cooled to 0° C. in an ice bath. After stirring 15 min, ethylene carbonate (7.6 mL, 10 g, 110 mmol, 2.0 equiv) was added. The bath was removed, and the reaction mixture was stirred for 15 h. The mixture was treated with 4 M aq K2CO3 (90 mL), heated at reflux for 5 h, and diluted with H2O (200 mL). After allowing the hot mixture to cool for 15 min, more H2O (100 mL) and then hexanes (100 mL) were added. The mixture was shaken vigorously and then allowed to separate. Crystals formed and stayed with the top organic layer. The aqueous layer was separated, and the crystals were collected by vacuum filtration and washed with hexanes (2×50 mL). The crystals were dissolved in Et2O/EtOAc (1:1; 200 mL), and the solution was dried (Na2SO4), filtered, and concentrated (75° C.) to give the title compound as an off-white crystalline solid (6.86 g, 59.6%). HRMS Calculated for C12H15N2O: m/z 203.1184. Found: 203.1168.
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