Tributylphosphine → 7-Bromo-8-(5-fluoro-2-methylphenoxymethyl)-1,3,3-trimethyl-3,4-dihydro-1H-quinoxalin-2-one

Participants

Reaction Steps

A mixture of 7-bromo-8-hydroxymethyl-1,3,3-trimethyl-3,4-dihydro-1H-quinoxalin-2-one (Reference Compound No. 1, 805 mg, 2.69 mmol), 5-fluoro-2-methylphenol (382 μL, 3.50 mmol), and tri-n-butylphosphine (874 μL, 3.50 mmol) was dissolved in anhydrous tetrahydrofuran (25 mL), 1,1′-(azodicarbonyl)dipiperidine (883 mg, 3.50 mmol) was added thereto, and then the mixture was stirred at room temperature for 1 hour. 5-Fluoro-2-methylphenol (382 μL, 3.50 mmol), tri-n-butylphosphine (874 μL, 3.50 mmol), and 1,1′-(azodicarbonyl)dipiperidine (890 mg, 3.53 mmol) were added thereto and it was furthermore stirred for 20 minutes. After hexane (15 mL) was added to the reaction mixture and the precipitated solids were filtered out, the filtrate was concentrated under reduced pressure and the obtained residue was purified by silica gel column chromatography (hexane-ethyl acetate) to give the titled reference compound (900 mg) as a colorless solid. (Yield 82%)

Provenance & Evidence