Acyl nitrates mixed anhydrides

Benzoyl nitrate C6H5C00N02 (prepared by reacting silver nitrate with benzoyl chloride) can in certain cases be a useful nitrating agent (Francis [181]). For example, thiophene is nitrated with this compound in theoretical yield, while if conventional methods are used, only a low yield is obtained and this only with great difficulty. 

Battegay and Brandt [181a] succeeded in nitrating anthracene to 9-nitro-anthracene with 70% yield by heating anthracene with pyridine nitrate and excess of pyridine to 125°C. Naphthalene was nitrated to a-nitronaphthalene (40% yield) at 130°C in presence of zinc chloride. 

Okoli [181b] has prepared piciylpyridinium nitrate I by acting on picrylpyndi-nium chloride with nitric acid or metal nitrates  

Okon and Hermanowicz [181c] have found that the nitrate I can serve as a nitrating agent. 

Thus the authors prepared a- nitronaphthalene from naphthalene with the yield of 80% by warming I with naphthalene. In a similar way toluene was nitrated at 80°C to 2,4-dinitrotoluene (yield 65%). By warming chloroform with I at 40-50°C chloropicrine resulted with the yield of ca. 30%. 

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