Study on the synthesis of o-cresol and m-cresol by hydrolysis of o-chlorotoluene

The important fine chemical industry intermediates——o-cresol and m-cresol were synthesized via basic hydrolysis of o-chlorotoluene in 25% NaOH solution at a temperature of 280 ℃ and a pressure of 5.1 MPa in the presence of SUNA catalyst,with the ratio of o-cresol and m-cresol equating to 1∶1.The total yield could reach a highest value of 86.0%,and at a suitable processing condition the overall yield could reach 83.0%.The by-products anisole and biphenyl cresol could be used as heat transfer oil,and the excess NaOH and by-product NaCl could be transformed into the raw material sodium fluosilicate,which was used to prepare ceramic.The optimum molar ratio of o-chlorotoluene and NaOH was 1.0∶3.0,with the reaction time equating to 5 h.