124188-13-2Relevant articles and documents
ipso Nitration in p-halophenyl ethers
Clewley, Robin G.,Fischer, Alfred,Henderson, George N.
, p. 1472 - 1479 (2007/10/02)
Addition of nitronium ion ipso to halogen occurs on nitration of the p-haloanisoles in acetic anhydride at -60 deg C.In the cases of p-fluoro- and p-chloro-anisole, addition of the nitronium ion is reversible and only small amounts of ipso products are obtained.With p-bromoanisole nitrodebromination occurs.When p-halophenyl ethers containing a trapping substituent, e.g., 2-(4-chlorophenoxy)-2-methylpropanoic acid, are used as substrates, substantial amounts of the spiro diene with nitro ipso to halogen, e.g., 3,3-dimethyl-8-chloro-8-nitro-1,4-dioxaspirodeca-6,9-dien-2-one, can be isolated.The results demonstrate that extensive ipso attack at the halogen-substituted position is general in the nitration of p-halophenyl ethers.Key words: ipso nitration, ether, diene, p-haloanisole.