Potassium Hydroxide → HCID 18966362, compound

Participants

Reaction Steps

To a solution of 1 g (3.6 mmol) of 4,4-dimethyl-7-trimethylsilylethynyl-thio-chroman (Compound 47) in 10 ml of isopropyl alcohol was added 5 ml of 1N KOH solution. The reaction mixture was stirred at room temperature for 18 hours and the isopropanol was then removed under vacuum. The residue was extracted with ether and the ether extracts were combined and washed with dilute HCl solution, water and saturated NaCl solution, and were thereafter dried (MgSO4). The solvent was removed in vacuo to give impure 4-4-dimethyl-7-ethynyl-thiochroman (Compound 48) as a pale yellow oil. This mixture was used in the next step without further purification. A solution of 281 mg of this impure 4,4-dimethyl-7-ethynylthiochroman (Compound 48) and 384 mg (1.4 mmol) of ethyl 4-iodo-benzoate in 1 ml of triethylamine was placed in a heavy walled glass tube and degassed under nitrogen. The mixture was treated with 60 mg of cuprous iodide and 30 mg of bis (triphenyl phosphine) palladium (II) chloride. The reaction mixture was degassed again under nitrogen, and the tube was sealed. The reaction mixture was stirred at room temperature for 18 hours. The solvent was removed under high vacuum and the residue purified by flash column chromatography (silica; 3% EtOAC/hexane) to give the title compound as an off-white solid.

Provenance & Evidence