Bromobenzene and iodobenzene could also be chlorinated giving 4-bromochlorobenzene and 4-chloroiodobenzene in yields of 56% and 58%, respectively. For example, toluene gave a 45:55 ratio of 4-chlorotoluene and 2-chlorotoluene in 80% yield. Aromatic compounds have been chlorinated in good yield under mild conditions using a mixture of tin tetrachloride and lead tetraacetate in dichloromethane. Chlorobenzene, nitrobenzene, and benzoic acid were unreactive even when the reactions were carried out at 80 ☌. High conversions were achieved under these conditions and mixtures of ortho- and para-substituted products were obtained, for example chlorination of toluene gave a 70:30 ratio of 4-chlorotoluene and 2-chlorotoluene. KCl and oxone™ have also been used for the electrophilic chlorination of toluene, acetanilide, and phenol in acetonitrile at room temperature.
Several examples of electrophilic chlorination reactions that use either HCl or KCl in the presence of an appropriate oxidizing agent have already been discussed in the context of general methods for halides ( Section 2.12.1.2.1). Stanforth, in Comprehensive Organic Functional Group Transformations II, 2005 2.12.3.2.1 Aryl chlorides by electrophilic aromatic substitution
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