Nitration benzonitrile

Nitration using this reagent was first investigated, by Francis. He showed that benzene and some of its homologues bromobenzene, benzonitrile, benzoyl chloride, benzaldehyde and some related compounds, and phenol were mono-nitrated in solutions of benzoyl nitrate in carbon tetrachloride anilines would not react cleanly and a series of naphthols yielded dinitro compounds. Further work on the orientation of substitution associated this reagent with higher proportions of o-substitution than that brought about by nitric acid this point is discussed below ( 5.3.4). 

W. Hoffmann, "Reaction Calorimetry in Safety - the Nitration of 2,6-Disubstituted Benzonitrile", Chimia, 42, 62, (1989). 

Nitration of benzonitrile by addition to mixed nitrating acid had been effected uneventfully in 250 batches. Plant improvements led to the same dosing vessel being used alternately for the nitrile and mixed acids. Some nitration occurred in the uncooled and unstirred dosing vessel containing a little residual nitrile and an explosion occurred during the second batch in the modified plant. 

Diammino-silver Nitrate, [Ag(NII3)2]N03.—When aqueous ammonia is added to a solution of silver nitrate until the precipitate first formed redissolves and the solution is evaporated, a crystalline substance separates of composition [Ag(NH3)2]N03. The compound can also be formed by dissolving silver oxide in an anunoniaeal solution of ammonium nitrate, or by dissolving silver nitrate in benzonitrile and passing ammonia gas into the solution.2... 

Benzonitrile. 3 diozoniumhydroxide, NC.CgH4.N( -N).OH known only in the form of salts. Its Nitrate, NC.CBH4N2.O.N02, ndls or prisms, is expl... 

Hoffmann, W. (1989) Reaction calorimetry in safety the nitration of a 2,6-disubstituted benzonitrile. Chimia, 43, 62-7. 

Answer The meta substitution pattern of Xll-g looms as the major difficulty in this-synthesis. The ethoxy group is an ortho iara director while the cyano function is a meta director. It appears that an easy approach to take would be to nitrate benzonitrile, reduce the -NO, group to the amine, diazotizc, and treat the diazonium salt with ethanol. However, jl is not feasible to reduce the -NO, group of meta-nitrobenzonitrilc without also reducing the -CN group. 

Arrange the following compounds in order of their reactivity towards nitration and give the formulae of the major products of the reactions (a) benzene, benzonitrile, methoxybenzene, tri-fluoromethyObenzene (b) acetanilide, benzoic acid, chlorobenzene, acetophenone (c) phenol, ethyl benzoate, nitrobenzene, bro-mobenzene. 

Three hundred milliliters of concentrated sulfuric acid is added to 110 g. of powdered potassium nitrate, and the mixture is cooled to 10° in an ice-salt bath. Benzonitrile (100 g., 0.97 mole) is added dropwise with stirring. The addition requires about 3 hours, and the temperature of the mixture is held below 20° during the entire operation and for an additional hour. The thick reaction mixture is added with stirring to 2 1. of an ice-water mixture. The precipitated solid is collected by filtration and washed with water. The solid is stirred with dilute ammonia water, and the resulting mixture is filtered and washed until the ammoniacal filtrate is only slightly yellow. The product is recrystallized from dilute ethanol or acetic acid to give 88 g. (61%) of m-nitrobenzonitrile melting at 115-116°. 

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