An efficient and practical synthesis of mandelic acid by combination of complex phase transfer catalyst and ultrasonic irradiation

Mandelic acid was synthesized from benzaldehyde with chloroform in a 81% yield at 60 °C for 2 h by using triethylbenzylammonium chloride (TEBA) and poly(ethylene glycol)-800 (PEG-800) as a complex phase transfer catalyst under ultrasonic irradiation. The main advantages of this present method are that the reaction time is much shorter and the yield is higher than those of the classical method. p-Methoxymandelic acid was also obtained in a 84% yield under the same reaction conditions.