These common heterocyclic compound, 1145-01-3, name is 3,5-Diphenyl-1H-pyrazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. COA of Formula: C15H12N2
To a flame dried flask was added 3,5-diphenylpyrazole (0.21 g, 0.95 mmol), Selectfluor (0.76 g, 2.1 mmol), and dried, ground molecular sieves (3 A) (0.5 g) followed by dry acetonitrile (distilled from CaH2 and stored over molecular sieves) (3 mL) and the mixture was heated at 80 C (oil bath temp) under N2 for 40 min. The dark yellow solution was then diluted with EtOAc and filtered. The filtrate was evaporated onto silica gel and subjected to flash chromatography on silica gel using 10:1 hexanes/EtOAc as eluent to give first difluoropyrazole 2 (0.19 g, 74% yield) and then the hydrated difluoropyrazole 3 (0.054 g, 20% yield) as yellow solids. The products were recrystallized from hexanes (2) or cyclohexane (3) to give analytical samples as pale yellow crystals. Data for 4,4-difluoro-3,5-diphenyl-4H-pyrazole (2): mp 91.2-91.8 C. IR (ATR): 3071, 3054, 1594, 1582, 1556, 1497, 1447, 1379, 1353, 1339, 1220, 1101, 1021, 872, 777, 720, 698, 681 cm-1. 1H NMR (300 MHz, DMSO-d6): 8.05 (d, J = 7.5 Hz, 4H), 7.74-7.64 (m, 6H). 13C NMR (75 MHz, DMSO-d6): 161.8 (t, J = 22.7 Hz), 133.8 (s), 129.9 (s), 127.8 (s), 125.7 (t, J = 265.9 Hz), 124.7 (s). 19F NMR (282 MHz, DMSO-d6): -116.4 (s). Anal. calcd for C15H10F2N2: C, 70.30; H, 3.93; N, 10.93; found: C, 70.41; H, 4.02; N, 10.82. Data for 4,4-difluoro-3,5-diphenyl-4,5-dihydro-1H-pyrazol-5-ol (3): mp 105.6-106.3 C. IR (ATR): 3354, 3238 (broad), 1593, 1571, 1491, 1332, 1449, 1238, 1136, 1068, 1050, 1016, 964, 889, 778, 688, 656, 635 cm-1. 1H NMR (300 MHz, DMSO-d6): 8.77 (s, 1H), 7.69 (d, J = 7.2 Hz, 2H), 7.59-7.56 (m, 2H), 7.48-7.40 (m, 6H), 7.31 (s, 1H). 13C NMR (75 MHz, acetone-d6): 143.9 (dd, J = 22.5 Hz, 24.0 Hz), 136.8 (d, J = 2.3 Hz), 134.2 (s), 130.1 (s), 129.8 (s), 129.6 (s), 128.9 (s), 128.2 (d, J = 1.6 Hz), 126.2 (d, J = 1.6 Hz), 125.3 (dd, J = 251.7 Hz, 261.9 Hz), 92.9 (dd, J = 20.8 Hz, 32.4 Hz). 19F NMR (282 MHz, DMSO-d6): -103.4 (d, J = 259 Hz), -122.7 (d, J = 259 Hz). Anal. calcd for C15H12F2N2O: C, 65.68; H, 4.41; N, 10.21; found: C, 65.58; H, 4.39; N, 10.23.
The synthetic route of 3,5-Diphenyl-1H-pyrazole has been constantly updated, and we look forward to future research findings.