70771-66-3Relevant academic research and scientific papers
SYNTHESIS OF 3-CHLORO-2-HYDROXYBENZOIC ACID BY CARBOXYLATION OF ortho-CHLOROPHENOL.
Shakirov,Stolyanets,Bikkulov,Lapuka
, p. 833 - 836 (2007/10/02)
A description is given of the results of the study of the carboxylation of potassium and sodium ortho-chlorophenolates. The technique for carrying out the experiments, and also the method of analysis of the carboxylation products do not differ from the authors' previous work. It is shown that in the study of the influence of potassium and sodium cations on the carboxylation of ortho-chlorophenol by the Kolbe-Schmitt method, it was found that potassium ortho-chlorophenolate is a more promising starting material for the synthesis of 3-chloro-2-hydroxybenzoic acid. It was found that the presence of excess amounts of ortho-chlorophenol, potassium hydroxide, and also small amounts of moisture, leads to a deterioration in the reaction parameters. Optimal conditions of the process have been determined: temperature 170-180 degree C, time of reaction 2-2. 5 h, CO//2 pressure 1. 5-2. 0 MPa. Under these conditions, the yield of potassium 3-chloro-2-hydroxybenzoate reaches 87-89% at 84-85% conversion of potassium ortho-chlorophenolate.
