反应详情

23.30 g of sodium hydroxide was dissolved in 118 mL of water and was ice-cooled, to which 9.23 mL of bromine was added dropwise over 20 minutes and then a solution of 9.80 g of 1-(2-fluoro-4-methoxyphenyl)-1-ethanone in 88 mL of 1,4-dioxane was added dropwise over one hour at −10° C. The resultant reaction mixture was cooled to room temperature, to which water was added, and then an aqueous phase was separated therefrom. A solution of 7.23 g of sodium thiosulfate in 100 mL of water was added to the aqueous phase, and then 12M hydrochloric acid was further added until the pH value of this aqueous phase reached 2. The resultant precipitate was filtered therefrom and washed with water to yield 8.20 g of 2-fluoro-4-methoxybenzoic acid as white solid.

1. additionwas added dropwise over 20 minutes
2. customThe resultant reaction mixture
3. additionwas added
4. customan aqueous phase was separated
5. additionA solution of 7.23 g of sodium thiosulfate in 100 mL of water was added to the aqueous phase
6. addition12M hydrochloric acid was further added until the pH value of this aqueous phase
7. filtrationThe resultant precipitate was filtered
8. washwashed with water