The Synthesis of Thioglycolic Acid with Sodium Hydrosulphide under Common Pressure

Thioglycolic acid(TGA) was synthesized from thioglycolic acid and sodium hydrosulfide under common pressure.The conversion ratio of TGA can get 82%～87% under such optimal conditions as the pH 9.0 in 0.65～0.70?mol·L -1 NaHS solution, corresponding to 2.0～2.5?mol·L -1 ClCH 2COONa solution, the reaction temperature 55±1?℃, the time 12?min, and the molecular ratio of ClCH 2COONa/NaHS 1∶1.3.