Abstract During the preparation experiment of 2,4-dichlorophenoxyacetic acid, phenoxyacetic acid is prepared by Williamson recation with chloroacetic acid and phenol as materials under alkaline conditions based on the textbook. This method has led to the severe hydrolysis of chloroacetic acids and the oxidation of phenols in the experiment, which resulted in the poor quality and low yields of products. This paper improved this experiment as follow:chloroacetic acid was neutralized at 0℃; 1% of sodium hyposulfite as reductants was introduced; phenol first reacted with sodium hydroxide, then the such-prepared solution was added into sodium chloroacetate solution to react. Under the modified conditions, the quality of phenoxyacetic acid was improved and the yields could also increase to 95.2%.
YANG Yu-Feng. Improved Synthetic Route to Phenoxyacetic Acid in Preparation of 2,4-Dichlorophenoxyacetic Acid Experiment[J]. Chinese Journal of Chemical Education, 2016, 37(14): 42-44.
