SDS-Catalyzed Esterification Process to Synthesize Ethyl Chloroacetate

Using sodium dodecyl sulfate (SDS) as the catalyst, ethyl chloroacetate has been synthesized by esterification of chloroacetic acid and ethanol. Various factors that affected the esterification have been investigated, such as reaction time, different water-carrying agents, and amount of catalyst. The esterification yield of ethyl chloroacetate reached 97.1% with 1.2/1 molar ratio of ethanol to chloroacetic acid, 1.0% catalyst (molar percentage of chloroacetic acid), 2.5 hr reaction time, 5 mL cyclohexane as water-carrying agent, and reflux temperature. The catalytic activity of SDS is almost equal with Br⊘nsted acids, such as sodium hydrosulfate or p-toluene sulfonic acid. Its catalytic activity is greater than that of most Lewis acids. SDS can easily hydrolyze into sodium hydrosulfate, which plays an essential role during the esterification process. The advantage of this catalytic process is that it is environmentally friendly, with high esterification yield, which may meet the standards of green chemistry.