Mono-Chlorination of Acetic Acid

Selectivity is a major issue for the mono-chlorination of acetic acid to chloroacetic acid since second chlorination gives dichloroacetic acid and other chlorinated species including add chloride formation [132]. The removal of these impurities, especially of the dichloroacetic add is laborious and costly, either by crystallization or by reduction with a palladium catalyst. 

A yield of 85% was obtained with a falling film microreactor, which outperforms large-scale bubble column processing [132]. Selectivity was also superior with 0.05% dichloroacetic add formed. Conventional processing has much higher levels of impurity ( 3.5%). When both, temperature and pressure, were slightly 

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