Nucleophilic substitution nitramines

Diazophenol formation is most competitive when a nitramine substrate contains an electron-withdrawing nitro group ortho to the nitro group being displaced and hence meta to the nitramine functionality, assumedly because that site is then activated towards nucleophilic aromatic substitution. Heating nitramines in inert chlorinated solvents also favours diazophenol formation but this is suppressed by using urea or sulfamic acid as additives. 

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