Diethylamine → 3-Bromo-4-(1-octynyl)thiophene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 250 mL 4 necked RB flask equipped with a magnetic stirring bar, thermometer, rubber septum, argon inlet and reflux condenser with argon outlet (tubed to a silicon oil bubbler) is added 59.4 g (246 mmol) of 3,4-dibromothiophene, 44.0 g of diethylamine, 27.0 g (245 mmol) of 1-octyne, 148 mg of triphenylphosphine, 106 mg of copper iodide and 295 mg dichlorobis(triphenylphosphine) palladium(II). The mixture is heated with a silicon oil bath to 60° C. under argon with stirring for 40 hrs. The cooled mixture is then concentrated on a rotary evaporator at reduced pressure and the residue taken up in 200 mL of pentane and washed with 2×25 mL of water and the pentane phase dried over sodium sulfate and then concentrated on a rotary evaporator. The residue is then distilled at 55-60 ° C. and 0.40 torr to remove 2.3 g of unreacted 3,4-dibromothiophene. The residue was chromatographed through silica gel eluting with hexanes to yield 17.1 g of 3-bromo-4(oct-1-ynyl)thiophene as a light yellow-orange oil which was used directly to prepare 2-hexylselenolo[2,3-c]thiophene.

Herkunft & Nachweise