Reaction of 3-indolylphenyliodonium betaine with electrophilic agents

3-Indolylphenyliodonium chloride and bromide, respectively, were obtained by the action of hydrochloric and hydrobromic acids on 3-indolylphenyliodonium betaine. Pyrolysis of the chloride leads to a mixture of 2- and 3-chloroindoles, while pyrolysis of the bromide leads only to 3-bromoindole. 1-Benzyl-2-chloroindole is obtained in the reaction of the betaine with benzyl chloride. The betaine reacts with dimethyl sulfate to give an iodonium salt, the reaction of which with lithium chloride and ammonium chloride leads to 1-methyl-2-chloroindole.