Synthesis
To a solution of 4-Fluorobenzaldehyde (10 g, 80.6 mmol) in dry DMF (100 mL) were added pyrazole (5.5 g, 80.6 mmol) and K2C03 (12.2 g, 88.7 mmol). The resulting solution was stirred at 100 °C for overnight. After cooling to RT, the residue was treated with water and extracted with EA. The organic extracts were washed with water and brine, dried over anhydrous Na2SO4, filtered and concentrated to give a crude oil. The crude product was purified by recrystallization to afford 4-Pyrazol-1-yl-benzaldehyde (4 g, 29 percent).1HNMR (CDC13, 300 MHz) : 6.5-6.6 (s, 1 H), 7.7-7.8 (s, 1 H), 7.9-8.0 (d, 2 H), 8.0-8.1 (d, 2 H), 8.1-8.2 (s, 1 H), 10.0-10.1 (s, 1 H).
References
[1] ChemCatChem, 2014, vol. 6, # 8, p. 2373 - 2383
[2] Patent: WO2016/77232, 2016, A2. Location in patent: Page/Page column 51
[3] Tetrahedron, 2008, vol. 64, # 10, p. 2471 - 2479
[4] Bulletin of the Chemical Society of Japan, 2008, vol. 81, # 4, p. 515 - 517
[5] Inorganic Chemistry, 2010, vol. 49, # 1, p. 331 - 338
