Toluene → 7-tert-butyl-3,3-dimethyl-5-thiophen-2-yl-2H-1-benzofuran

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Reaction Steps

A mixture of 5-bromo-7-tert-butyl-2,3-dihydro-3,3-dimethylbenzo[b]furan (2.26 g, 8.0 mmol), 2-(tributylstannyl)thiophene (3.05 mL, 9.6 mmol), tetrakis(triphenylphosphine)palladium (0.92 g, 0.8 mmol), and 40 mL of toluene is heated under argon at reflux for 2 h. The reaction mixture is cooled to room temperature, diluted with ether, washed with 10% aqueous ammonium hydroxide solution and with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 6.44 g of a dark oil. Purification by flash column chromatography on silica gel (0.5% ethyl acetate-hexane) yields about 0.98 g (43%) of the title compound initially as a colorless oil, which solidifies upon standing: mp 61-63° C.

Provenance & Evidence