反应详情

A slurry of 5.00 g (15.6 mmoles) of methyl 4-(4-phenoxyphenoxy)benzoate from Example A, 0.28 g (50.0 mmoles) of potassium hydroxide, 50 ml of methanol and 50 ml of deionized water is refluxed for 48 hours. Methanol is added until the mixture is homogeneous. Aqueous hydrochloric acid is added until the solution is strongly acidified, and the slurry is cooled. The resulting precipitate is filtered, washed with 300 ml of deionized water and dried in air. It is recrystallized from a minimum volume of hot 2-1 by volume methanol and water solution to yield 4.40 g (92 percent yield) of 4-(4-phenoxyphenoxy)benzoic acid having a melting point of 185° C. as measured by DSC.

1. temperaturethe slurry is cooled
2. filtrationThe resulting precipitate is filtered
3. washwashed with 300 ml of deionized water
4. customdried in air
5. customIt is recrystallized from a minimum volume of hot 2-1 by volume methanol and water solution