Propyne → 6-Methoxy-2-methylbenzofuran

Participants

Reaction Conditions

Reaction Steps

A solution of 2-iodo-5-methoxy-phenol (39 g, 156 mmol) in dimethylformamide (300 mL) and N,N,N′,N′-tetramethylguanidine (150 mL) is treated with copper(I) Iodide (1.89 g, 9.82 mmol) and bis(triphenylphosphine)palladium(II) chloride (1.9 g; 2.71 mmol; 1.900 g). The mixture is cooled to −78° C. Propyne (100 g; 2.50 moles) is bubbled through the mixture for 1 hour. The reaction mixture is stirred and allowed to warm to room temperature gradually over 6 hours and stirred for 2 days. The reaction mixture is quenched with water (800 mL) and extracted with EtOAc (500 mL). The organic layers are dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product is purified via flash chromatography eluting with 10% EtOAc/Hexanes. The appropriate fractions are concentrated. The material is dried in vacuo to afford the title compound (17.5 g, 69%). 1H NMR (400 MHz, CDCl3): δ 7.31-7.29 (d, 1H), 6.95 (s, 1H), 6.81-6.79 (d, 1H), 6.26 (s, 1H), 3.81 (s, 3H), 2.40 (s, 3H).

Provenance & Evidence