2-Fluorophenol → 4-(2-Fluorophenoxy)benzoic acid

Participants

Reaction Steps

To a solution of 4-fluorobenzaldehyde (1.2 g, 10 mmol) and 2-fluorophenol (1.3 g, 12 mmol) in N,N-dimethylformamide (10 ml) was added potassium carbonate (2.8 g, 20 mmol) with stirring, and the resulting mixture was stirred at 100° C. for 16 hours. After cooling to room temperature, the reaction mixture was poured into water (20 ml) and extracted with ether. The extract was washed with a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. After filtration, the filtrate was evaporated in vacuo. Subsequently, to a solution of the residue obtained in a mixture of tetrahydrofuran (5 ml), t-butanol (10 ml), and water (5 ml) were added successively 2-methyl-2-butene (5.3 ml, 50 mmol), potassium dihydrogenphosphate (3.4 g, 25 mmol), and sodium hypochlorite (2.7 g, 30 mmol) with stirring, and the resulting mixture was stirred at room temperature for 2 hours. After stirring, the reaction mixture was poured into water (20 ml) and extracted with ether. Subsequently, to the aqueous layer was added a 1M aqueous sodium hydroxide solution (20 ml), and the resulting aqueous layer was acidified with a 10M aqueous hydrochloric acid solution (2 ml) and extracted again with ether. The extract was washed with a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. After filtration, the filtrate was evaporated in vacuo to afford the title compound (2.0 g) in a yield of 87% as a white crystalline solid.

Provenance & Evidence