STRUCTURE OF (3-CHLORO-2-HYDROXY-5-NITROPHENYL)-(2'-CHLOROPHENYL)IODONIUM HYDROXIDE INNER SALT

The reaction of phenols with phenyliodine diacetates, in general, leads to the formation of mixtures of products including acetoxyphenols and benzoquinones.1 A notable exception was the report by Fox and Pausacker2 that on treatment of 4-nitrophenol with phenyliodine diacetate they obtained in 85% yield a yellow crystalline compound, to which they assigned structure 1. On heating 1, the o-iododiphenyl ether 2 was obtained.In a synthesis of specific chlorinated dibenzofurans, 3 we have used the oxidation of chlorinated 4-nitrophenols with chlorinated phenyliodine diacetates to yield the o-iododiphenyl ethers, with subsequent ring closure to the dibenzofurans through the pheniodoxin-5-ium iodide. In the course of this synthetic work,4 we examined the structure of one of the compounds analogous to 1. We report the structure of this compound to be (3-chloro-2-hydroxy-5-nitrophenyl)- (2'-chlorophenylfiodonium hydroxide inner salt (3), based on chemical, spectral, and X-ray crystallographic data. This is the first reported example of a phenoxide-iodonium betaine. © 1979, American Chemical Society. All rights reserved.