Acetic Acid → HCID 11528980, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 2′-hydroxyacetophenone (1.36 g, 10 mmol) in 20 mL anhydrous pyridine was added 3-fluoro-4-methoxybenzoyl chloride (1.89 g, 10 mmol) and the reaction mixture was stirred at rt for 15 h under a nitrogen atmosphere. The reaction mixture was poured into 200 mL of 2 N HCl. The formed solid was isolated by filtration, washed with water and dried under vacuum to give a white solid (2.76 g, 95.7%). The compound (2.68 g, 9.3 mmol) was dissolved in 10 mL anhydrous pyridine. Powdered potassium hydroxide (1.57 g, 27.9 mmol) was added and the reaction mixture was stirred at rt overnight under nitrogen. Water (100 mL) was added, the solid was isolated by filtration and washed with water to give a yellow solid (1.83 g, 68%). The compound (1.78 g, 6.17 mmol) was suspended in 15 mL glacial AcOH. Five drops of conc. HCl was added and the reaction mixture was stirred at 110° C. for 2 h, then cooled to rt. Water (100 mL) was added. The formed solid was separated by filtration, washed with water and dried under vacuum to give 2-(3-fluoro-4-methoxyphenyl)chromen-4-one as a white solid (1.62 g, 97%). 2-(3-Fluoro-4-methoxyphenyl)chromen-4-one (1.6 g, 5.92 mmol) was suspended in 40 mL of Hi. Glacial AcOH (15 mL) was added and the reaction mixture was stirred at 110° C. for 4 h, then cooled to rt. Water (200 mL) was added, and the solid was isolated by filtration, washed with water and dried under vacuum. The crude compound was washed with 1:1 dichloromethane and methanol (15 mL) to give 1.1 g of 2-(3-fluoro-4-hydroxyphenyl)chromen-4-one (72%) as a pale yellow solid. MS (ES) m/z: 257.91 (M+1), 256.88 (M); Mp. 275-276° C.

Provenance & Evidence