Nitrogen → 4-(4-fluoro-3-nitrophenyl)-1-methyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A solution of 4-bromo-1-fluoro-2-nitrobenzene (2 g, 9.095 mmol) in 1,4-dioxane (20 ml) was degassed by N2 bubbling for 5 min. 1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.27 g, 10.91 mmol, 1.2 eq.) and aqueous sodium carbonate (2.89 g, 27.27 mmol, 3.0 eq.) were added and the mixture was degassed for another 15 min. Pd(PPh3)2Cl2 (0.638 g, 0.909 mmol, 0.1 eq.) was added sequentially and the mixture was further degassed for 15 min and then heated at 90° C. for 2 h. The mixture was quenched and extracted as in Intermediate Example 5(c). The solvent was distilled off to afford the crude residue which was purified by column chromatography (60-120 silica gel, 40-50% ethyl acetate in hexane) to yield the product in 79% yield (1.6 g). 1H NMR (300 MHz, DMSO-d6): δ 8.32-8.26 (m, 2H), 8.0-7.97 (m, 2H), 7.62-7.55 (m, 1H).

Provenance & Evidence