4-bromo-7-methoxy-1-benzofuran

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A toluene (4 ml) suspension of (4a′R,8a′S)-octahydro-1′H -spiro[cyclobutane-1,2′-quinoxaline](180 mg, 0.998 mmol), 4-bromo-7-methoxybenzofuran (250 mg, 1.10 mmol), Pd(OAc)2 (11.2 mg, 0.0499 mmol), t-Bu3P.HBF4 (14.5 mg, 0.0500 mmol), and NaOt-Bu (135 mg, 1.40 mmol) was stirred for 4 hours under reflux in a nitrogen atmosphere. The reaction solution was cooled to room temperature. Then, water (0.5 mL) and AcOEt (10 mL) were added thereto, and the mixture was stirred. MgSO4 was further added thereto, and the mixture was stirred. Insoluble matter was filtered, and the residue was washed with AcOEt (5 mL×2). Then, the filtrate was concentrated under reduced pressure. The obtained residue was purified by basic silica gel column chromatography (Hex-AcOEt) to obtain a colorless amorphous solid. This solid was crystallized from hexane (1 mL) to obtain (4a′R,8a′S)-4′-(7-methoxybenzofuran-4-yl)octahydro-1′H-spiro[cyclobutane-1,2′-quinoxaline](107 mg, yield: 35%) in a white powder form. under reflux in a nitrogen atmosphere the mixture was stirred Insoluble matter was filtered the residue was washed with AcOEt (5 mL×2) Then, the filtrate was concentrated under reduced pressure The obtained residue was purified by basic silica gel column chromatography (Hex-AcOEt) to obtain a colorless amorphous solid This solid was crystallized from hexane (1 mL)