Toluene → 3-Bromo-5-thiophen-3-yl-pyridine

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a mixture of 3,5-dibromopyridine (5 g, 21 mmol), distilled water (35 mL), toluene (140 mL), ethyl alcohol (35 mL), 3-thiopheneboronic acid (2.8 g, 22 mmol), sodium carbonate (4.67 g, 44.1 mmol) and tetrakis(triphenylphosphine) palladium (1.22 g, 1.05 mmol) were stirred. This black suspension was heated at 75° C. for 20 h. After cooling to room temperature, the mixture was diluted with distilled water (200 mL) and extracted with ethyl acetate (2×200 mL, then 100 mL). The combined organic phases were dried with MgSO4, filtered and concentrated by rotary evaporation, producing 17 g of a purple oil. Purification by column chromatography on silica gel, using cyclohexane:ethyl acetate (95:5) as eluent, afforded 2.9 g (58%) of white crystals, mp 58° C.

Provenance & Evidence