Synthesis Of 4-(2,4-dichlorophenoxy) Phenol

4-(2,4-Dichlorophenoxy)phenol is a kind of pharmaceutical intermediate, named 2,4-dichloro-4'-hydroxyldiphenylether also. It is a kind of intermediate for making herbicide and acts as bactericide as well. Up to now, there hasn't openly reported the study on synthesis of 4-(2,4-dichlorophenoxy)phenol in china. However, the study on synthesis and application of the intermediate was reported in the early 1970's overseas.Owing to its far-ranging application, the intermediate is intended to synthesize from 2,4-dichlorophenol and p-chloronitrobenzene by etherification, reduction of nitro group, diazotization-hydrolysis reaction in the paper, namely.So it is very practical to study a feasible way of synthesizing 4-(2,4-dichlorophenoxy)phenol and then optimize the way as to industrialized produce it domestically as much as possible. It being the fact, every unit-reaction of synthesizing the compound is made an attempt to research and etherification and reduction of nitro group are stressed to search after in the paper. Someconclusions are come to as follows.1. Synthesizing 2,4-dichloro-4'-nitryldiphenylether by solvent way is more safer and steadier compared with nonsolvent way. On the basis of experiment, the solvent way is improved on. The water in the reflux liquid is separated by use of a trap of the Dean-Stark type by a binary azeotrope consisting DMF and toluene. The improved way simplifies process, reduces cost and enhances yield and quality.2. Two ways of iron reduction and hydrazine hydrate reduction to prepare 4-(2,4-dichlorophenoxy)aniline are searched after. Although the quality is pretty much the same thing, hydrazine hydrate reduction has good selectivity, simple process, short reaction time, small pollution and high pure degree and yield, as against iron reduction. In summary, hydrazine hydrate reduction is more simple, reasonable and practical in the matter of industrialisation.3. Diazotization-hydrolysis reaction in the literature has bad reiteration, thus it is improved on and optimized.4. The intermediate is synthesized from 2,4-dichlorophenol and p-chloronitrobenzene by etherification reaction, reduction reaction of nitro group, diazotization-hydrolysis reaction to get tiptop total yield of 57.6% in the paper. Structure of 4-(2,4-dichlorophenoxy)phenol is primarily identified by TLC, IR and 'HNMR.