Sulfuric Acid → HCID 67387644, compound

Participants

Reaction Conditions

Reaction Steps

To a 500 mL flask was added 3-bromo-2-fluoro-6-(2-fluoro-4-methoxyphenoxy)benzoic acid (43.45 g, 121 mmol) in conc. sulfuric acid (127 mL, 1815 mmol). The sticky mixture was heated at 60° C. for 2.5 h. The reaction was then poured into ice water very slowly with stirring. The yellow precipitate was filtered through Buchner funnel and washed excess water. Then the filter cake was put in a beaker and carefully neutralized with mixture of 2N aqoueous NaOH solution and saturated aqueous NaHCO3. The mixture was stirred for half an hour and filtered by Buchner funnel again. The light yellow solid was washed by excess water and finally little amount of acetone to yield 2-bromo-1,5-difluoro-7-methoxy-9H-xanthen-9-one (23.34 g, 68.4 mmol, 56.6% yield) as light yellow solid. It was used for next step without further purification.

Provenance & Evidence