Ethyl Acetate → 1-phenyl-5-(2,4,5-trifluorophenyl)-1H-pyrazole-4-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 1-phenyl-5-(2,4,5-trifluorophenyl)-1H-pyrazole-4-carboxylate (459 mg, 1.325 mmol) in THF (5 mL) was added LAH (1.988 mL, 1.988 mmol as a 1 M THF solution) at room temperature and the reaction was then heated at 50° C. for 2 hours. The reaction was quenched with addition of 0.2 mL of water, 0.2 mL of 0.5 N NaOH and then 0.2 mL of water. The suspension was diluted with ether and was filtered through celite. Upon removal of the volatiles, the crude residue was purified by flash chromatography to afford an oil. The oil was then dissolved in 5 mL of CH2Cl2 and Dess-Martin periodinane (233.8 mg, 0.768 mmol) was added. The suspension was stirred at room temperature for 16 hours. The mixture was poured into EtOAc and was washed with brine. The organic phase was dried with Na2SO4, filtered and concentrated. The crude residue was purified by flash chromatography using a gradient of ethyl acetate/hexanes to afford the title intermediate as white solid.

Provenance & Evidence