The preparation of the 2, 6-dichlorophenylacetic acid:
the method comprises the following steps: 2, 6-dichlorotoluene is used as a raw material, and is catalyzed by a complex catalyst formed by transition metal and a ligand (wherein, a transition metal catalyst precursor is preferably palladium chloride, an oxidant is preferably TBP (tert-butyl peroxy ether), and a ligand is preferably Xantphos (4, 5-bis (diphenylphosphino) -9, 9-dimethyl xanthene)) in the presence of an alcohol and a catalyst and an oxidant to obtain 2, 6-dichlorophenylacetic acid, and the ethyl 2, 6-dichlorophenylacetate is prepared by hydrolysis and acidification, wherein the total yield is 68.4%. See patent document US2013303798, the reaction procedure is described as synthetic route 1.
In the above synthetic route 1, the preparation process of the intermediate ethyl 2, 6-dichlorophenylacetate requires the use of carbon monoxide for high-temperature and high-pressure reaction, and has poor operation safety, high equipment requirement, high cost, and is not favorable for cost reduction and green production of 2, 6-dichlorophenylacetic acid.
