Diazophenols from the rearrangement of o-nitroarylnitramines

The nitration of 2-amino-4,6-dinitrotoluene (63) with a mixtnre of nitric acid in sulfuric and acetic acids yields 2-diazo-3-methyl-4,6-dinitrophenol (65) in 75 % yield without isolation of the intermediate nitramine (64).  

The nitration of both 4-methyl- and 4-chloro-2,6-dinitrotoluenes (66 and 67) with mixed acid in acetic acid at subambient temperature allows the isolation of the nitramines, (68) and (69), respectively. Thermolysis of (68) and (69) in refluxing methylene chloride yields the corresponding diazophenols, (70) and (71), respectively. Scilly and co-workers isolated 2-diazo-4,6-dinitrophenol (DINOL) (53) from the thermolysis of fV,2,3,5-tetranitroaniline (73) in ethyl acetate at 60 °C. 

Unsymmetrical arylnitramines with two nitro groups positioned ortho to the nitramino functionality can yield two isomeric diazophenol products. The diazophenols (76) and (77) were isolated in a 4 1 ratio from the nitration of 3-amino-2,6-dinitrotoluene (74) with mixed acid, the reaction proceeding via the intermediate nitramine (75).  

Chemists at the Naval Air Warfare Center (NAWC), China Lake, have conducted much research into the nitration of various substituted anilines as an indirect route to highly nitrated arylene hydrocarbons (Section 4.5). On numerous occasions these chemists found that diazophenols are formed as by-products and sometimes as the main or only product of a reaction. During these studies the diazophenols (65) and (78-81) ° were isolated and characterized. These diazophenols were screened for use as explosive components of both percussion and stab-sensitive primary explosive compositions.  

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