87-65-0Relevant articles and documents
The use of polymeric sulfides as catalysts for the para-regioselective chlorination of phenol and 2-chlorophenol
Smith, Keith,Hegazy, Amany S.,El-Hiti, Gamal A.
, p. 1 - 12 (2019/11/20)
Various poly(alkylene sulfide)s have been synthesized and used as catalysts to enhance the para-regioselectivity in chlorination of phenol and 2-chlorophenol using freshly distilled sulfuryl chloride in the presence of AlCl3 as an activator. Poly(alkylene sulfide)s having alternating spacers, one having three methylene groups and the second having three, six or nine methylene groups were the most para-regioselective catalysts in chlorination of both phenol and 2-chlorophenol. For example, chlorination of phenol and 2-chlorophenol in the presence of optimal examples of such poly(alkylene sulfide)s gave 4-chlorophenol and 2,4-dichlorophenol as the major products in 94.8 and 95.4% yields, respectively, compared with 75.4 and 55.0% yields in the absence of catalysts. In addition, double chlorination of phenol in the presence of poly(alkylene sulfide)s gave 2,4-dichlrophenol in up to 97.1% yield compared with only 58.6% in the absence of catalysts.
Method for producing high purity 2, 4 - dichlorophenol
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Paragraph 0107-0115, (2019/07/04)
The invention provides a method for producing high purity 2, 4 - dichlorophenol, including: (1) heating and melting the raw materials, the mixed catalyst is added in the raw material, wherein the feedstock is phenol, O-phenol or [...] in at least one of, the mixed catalyst is phenyl sulfide, mixture of ferric chloride and trifluoromethanesulfonic acid; (2) to maintain the temperature of the material is 40 - 100 °C, to the material to carry out chlorination chlorinating agent is filled in the catalytic reaction to obtain 2, 4 - dichlorophenol crude product, the chlorinating agent is chlorine or sulfuryl chloride in at least one of; (3) to said 2, 4 - dichlorophenol crude melt crystallization, to obtain 2, 4 - dichlorophenol product. In this invention the states the chlorizating agent can be a chloride, can also be chlorine, the two can achieve higher conversion rate of raw materials, the application in the catalytic chlorination reaction the crude product obtained without rectification, only through the melt crystallization to obtain the purity 99% of the 2, 4 - dichlorophenol product.
Ammonium Salt-Catalyzed Highly Practical Ortho-Selective Monohalogenation and Phenylselenation of Phenols: Scope and Applications
Xiong, Xiaodong,Yeung, Ying-Yeung
, p. 4033 - 4043 (2018/05/22)
An ortho-selective ammonium chloride salt-catalyzed direct C-H monohalogenation of phenols and 1,1′-bi-2-naphthol (BINOL) with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) as the chlorinating agent has been developed. The catalyst loading was low (down to 0.01 mol %) and the reaction conditions were very mild. A wide range of substrates including BINOLs were compatible with this catalytic protocol. Chlorinated BINOLs are useful synthons for the synthesis of a wide range of unsymmetrical 3-aryl BINOLs that are not easily accessible. In addition, the same catalytic system can facilitate the ortho-selective selenylation of phenols.