反应详情

Finally, a further possibility for preparing 2,4,5-trimethylphenylacetic acid is to initially react pseudocumene with glyoxylic acid to give 2,4,5-trimethylmandelic acid (Atti Accad., Lettere Arti Palermo, Pt. I24 (1965) 19–33) and then to reduce it to 2,4,5-trimethylphenylacetic acid (J. Amer. Chem. Soc. 58 (1936) 629–35). However, the preparation of 2,4,5-trimethylmandelic acid by the process specified has the disadvantage that the 2,4,5-trimethylmandelic acid which has already formed reacts with further pseudocumene under the customary reaction conditions and thus forms considerable proportions of 2,2′,4,4′,5,5′-hexamethyldiphenylacetic acid (Atti Accad., Lettere Arti Palermo, Pt. I24 (1965) 19–33), which of course reduce the yield and make necessary additional purification steps.