2-Iodothiophene → 2-(Thien-2-ylethynyl)benzothiophene

Participants

Reaction Steps

The reaction mixture from Step A containing 2-trimethylsilylethynylbenzothiophene was stirred, and 4.96 grams (0.0157 mole) of tetrabutylammonium fluoride trihydrate and 10.1 grams (0.173 mole) of potassium fluoride were added. Upon completion of addition, the reaction mixture was stirred at ambient temperature for 4.5 hours. After this time 36.3 grams (0.173 mole) of 2-iodothiophene was added via syringe. Upon completion of addition, the reaction mixture was stirred at ambient temperature for 60 hours. After this time the reaction mixture was dissolved in diethyl ether and a small amount of methylene chloride, and it was washed with two portions of an aqueous solution of 10% ammonium chloride, one portion of water and one portion of an aqueous solution saturated with sodium chloride. The organic layer was dried with sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was subjected to column chromatography on silica gel. Elution was accomplished with hexane and 20% methylene chloride in hexane. The appropriate fractions were combined and concentrated under reduced pressure, yielding 35.1 grams of 2-(thien-2-ylethynyl)benzothiophene.

Provenance & Evidence