Hydrochloric Acid → 7,8-Difluoro-2-pentyl-5-(4-propylcyclohexylethynyl)chroman-6-ol

Participants

Reaction Steps

8.0 g (20.9 mmol) of 7,8-difluoro-5-iodo-2-pentylchroman-6-ol are stirred at 50° C. for 19 h together with 4.72 g (31.4 mmol) of 1-ethynyl-4-propylcyclohexane in the presence of 441 mg (0.63 mmol) of bis(triphenylphosphine)palladium(II) chloride and 120 mg (0.63 mmol) of copper(I) iodide in 90 ml of triethylamine. After cooling, the batch is added to ice/water and acidified using hydrochloric acid. The mixture is extracted a number of times with MTBE, and the combined extracts are washed with water and sat. sodium chloride soln. The solution is dried using sodium sulfate and concentrated to dryness. The residue is purified by column chromatography (SiO2, 1-chlorobutane). The phenol obtained is used directly for the following reaction.

Provenance & Evidence