Hydrochloric Acid → HCID 10798663, compound

Participants

Reaction Steps

To a solution of commercially available 4-iodobenzotrifluoride (11.76 mL, 80 mmol) in THF (70 mL) at −40° C. was added isopropylmagnesium chloride (2 M in THF, 41.2 mL, 88 mmol) within 5 min keeping the internal temperature below −20° C., stirring was continued at −20 to 0° C. for 40 min. ZnCl2 (1M in THF, 88 mL, 88 mmol) was added, the cooling bath was removed and replaced with a water bath, the mixture was allowed to reach 23° C. and stirred at 23° C. for 45 min resulting in a light yellow suspension. Pd(PPh3)4 (924 mg, 1 mol %) and trans-crotonyl chloride (90%, 9.38 mL, 88 mmol) were added dropwise at 23° C. (exothermic reaction (!), keeping the internal temperature at ˜35° C. by water bath cooling) and stirring was continued at 23° C. for 1 h. Poured into icecold 0.5 N HCl, extracted with EtOAc, washed with sat. NaHCO3-sol. and brine, dried over MgSO4. Removal of the solvent in vacuum left a red oil which was purified with chromatography with heptane to heptane:TBME (9:1) to give the (E)-1-(4-trifluoromethyl-phenyl)-but-2-en-1-one as a yellow liquid (18.37 g, quant., 93% purity).

Provenance & Evidence