Halogenating agents, for

In addition to the applications indicated on p. 858. hypohalous acids are useful halogenating agents for Ixjth aromatic and aliphatic compounds. HOBr and HOI are usually generated in silii. The ease of aromatic halogenation increa.ses in the sequence OCl < OBr < Ol and is facilitated by salts of Pb or Ag. Another well-known reaction of hypohalites is their cleavage of methyl ketones to form carboxylates and haloform ... 

Phenylseleninyl chloride is also an efficient regio para- selective halogenating agent for activated aromatics such as phenol, phenol ethers and anilines958. Bis(4-chlorophenyl) selenide/Lewis acid mixtures chlorinate toluene preferentially at the para position959. Porphyrines are also chlorinated by PhSeCl and PhSeCl3960. PhSeBr brominates 3-keto steroids at the a-position961. 

The coordination chemistry of Mn111 with the halides210,335,572 is distinctly more limited than that of Mn" the former are good halogenating agents for hydrocarbon compounds and the only binary compound able to exist at normal temperatures is MnF3. Black solids, stable only below — 40°C, probably represent MnCl3, but the bromo and iodo compounds have never been observed. 

Hypohalous acids are useful halogenating agents for both aromatic and aliphatic compounds, the ease of aromatic halogenation increasing in the order OCl <... 

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