4-Methoxyphenoxyacetic acid

150-76-5

79-11-8

1877-75-4

Compounds B1-7 were prepared by similar methods. In the synthesis of B1, monochloroacetic acid (0.04 mol, 3.78 g) was first dissolved in 15 mL of deionized water under stirring and ice bath conditions. Subsequently, 25% NaOH solution was added drop by drop and the pH was adjusted to 9-10 to produce sodium chloroacetate solution. In another vessel, NaOH (0.03 mol, 1.20 g), 15 mL of deionized water, 5 mL of ethanol and phenol (0.04 mol, 3.76 g) were mixed, and the above sodium chloroacetate solution was added slowly with stirring. After addition, stirring was continued for 20 minutes, followed by dropwise addition of sodium chloroacetate solution and the reaction mixture was heated to 105 °C and refluxed for 5 hours. After completion of the reaction, the mixture was cooled to room temperature and acidified with dilute hydrochloric acid to pH 1-2. The precipitate was collected by filtration, washed several times with dilute hydrochloric acid, and after recrystallization and drying in vacuum, the white solid product phenoxyacetic acid (B1) was obtained.