Reaction with nitryl chloride

Deville first synthesized dinitrogen pentoxide in 1849 by reacting silver nitrate with chlorine gas. This reaction probably involves the initial formation of nitryl chloride and, accordingly, dinitrogen pentoxide can also be formed from the reaction of nitryl chloride or nitryl fluoride with a metal nitrate. These reactions are more of theoretical interest than of any practical value. 

On the other hand Price and Sears [107] studied the reactions of nitryl chloride with various aromatic compounds in the presence of aluminium chloride, and found that phenol, anisole and naphthalene tended to undergo oxidative degradation. In the case of naphthalene they obtained a 31% yield of a- nitronaphthalene, whereas with anisole and phenol they were able to isolate only traces of nitro compounds without any evidence of chlorination. 

Nitrosyl fluoride was also made from NO2 and C0F3 and by the reaction of nitryl chloride with hydrogen fluoride ... 

In Lewis acid halide catalyzed nitrations with nitryl chloride the question arises are these reactions nitronium salt nitratiors according to the ionization... 

Nitroxanthine is produced is produced as the major nitration product in reactions of 2 -deoxy-guanosine or ca//thymus DNA with nitryl chloride produced by mixing nitrite with hypochlorous acid, and 8-nitroguanidine was a minor product in these reactions (Chen et al. 2001). Formation of 8-nitroxanthine was also detected by xanthine reaction with various reactive nitrogen species, including nitryl chloride, peroxynitrite, nitronium tetra-fluoroborate, and heated nitric and nitrous acids. 

Olefins may be chloronitrated with nitryl chloride. In this reaction, the nitro group appears to add to the olefinic carbon atom bearing the larger number of hydrogens. 

In the photolysis of difiuorodiazirine (218) a singlet carbene was also observed (65JA758). Reactions of the difiuorocarbene were especially studied with partners which are too reactive to be used in the presence of conventional carbene precursors, such as molecular chlorine and iodine, dinitrogen tetroxide, nitryl chloride, carboxylic acids and sulfonic acids. Thus chlorine, trifiuoroacetic acid and trifiuoromethanesulfonic acid reacted with difiuorodiazirine under the conditions of its photolysis to form compounds (237)-(239) (64JHC233). 

A novel, mild system for the direct nitration of calixarenes has been developed using potassium nitrate and aluminum chloride at low temperature. The side products of decomposition formed under conventional conditions are not observed in this system, and the p-nitro-calixarenes are isolated in 75-89% yields.17 Such Friedel-Crafts-type nitration using nitryl chloride and aluminum chloride affords a convenient system for aromatic nitration.18 Nitryl chloride was previously prepared either by the oxidation of nitrosyl chloride or by the reaction of chlorosulfonic acid with nitric acid. However, these procedures are inconvenient and dangerous. Recently, a mixture of sodium nitrate and trimethysilyl chloride (TMSC1) has been developed as a convenient method for the in situ generation of nitryl chloride (Eq. 2.6). 

An older preparation method involves passing dry chlorine gas slowly over dry silver nitrate heated to about 100°C. The gaseous reaction products are allowed to cool to low temperature. After several hours, nitryl chloride condenses to a pale yellowish-brown liquid. Chlorine is removed by purging with CO2. 

Nitryl chloride may he identified by its mass spectra. The characteristic mass ions are 81, 83, 46, 35, and 37. Alternatively, nitryl chloride maybe identified from its physical and chemical properties (See Reactions). The wet analytical method involves treatment with an excess solution of NaOH and titrating the excess NaOH with a standard solution of H2SO4. Alternatively, nitryl chloride is decomposed in water, and the acids HNO3 and HCl formed are measured by titration or the NO and CH determined by ion specific electrodes or ion chromatography. 

Weston and Ogg449 found that nitryl chloride was produced in the reaction of nitrogen pentoxide with nitrosyl chloride... 

The precise nature of the reaction path is ambiguous, because the same products would be obtained regardless of whether an oxygen atom or a chlorine atom were transferred. As they pointed out in their paper, this ambiguity can be resolved by using nitryl chloride with isotopically labeled nitrogen. Pertinent to this question are the calculations of Herschbach, Johnston, Pitzer, and Powell,199 who computed pre-exponential factors based on two alternative activated complexes... 

Critical surveys have shown that the older methods for the preparation of nitryl chloride are inefficient and yield impure products.1-7 Reasonably pure nitryl chloride was first prepared by Schumacher and Sprenger1-3 in 1929 by the reaction of nitrosyl chloride with ozone the preparation from chlorosulfonic acid and nitric acid was reported later.4 Recently, Schmeisser has obtained nitryl chloride from nitrogen(Y) oxide and phosphorus(V) chloride.5 The reaction of chlorosulfonic acid with nitric acid8-10 is probably the most convenient method for preparing large quantities of nitryl chloride of satisfactory purity. 

It was found by Steinkopf and Kiihnel [106] that the so-called nitryl chloride is an agent that both nitrates and chlorinates aromatic hydrocarbons. However, the reaction could be selective. Thus, only o- nitrophenol was formed when nitryl chloride interacted with phenol below room temperature, but at room temperature 2,4-dichloro-6-nitrophenol was obtained. Naphthalene was chlorinated and nitrated simultaneously to give a- nitro- and a- chloro-naphthalene. 

With excess nitrosyl chloride, a chloronitro product is obtained in certain cases, a wide variety of ste-roid-5-enes giving 5a-chloro-6p-nitro derivatives in good yield (CH2CI2/CG4, to 0 C, 2-24 h). Nitryl chloride adds to terminal alkenes (56-80%) and to aoylic acid derivatives (refs. 239,240 and references cited therein) at temperatures close to amlrient. The reaction iq>peais to be a radical one, the NO2 entering the terminal position whatever the electronic requirement of the alkene. 

Nitryl chloride reacts with zinc, mercury, and bismuth to form mixtures of the metal chlorides and nitrates, but does not react with copper, magnesium, iron, aluminum, or tin at 243 K. In the reaction with ammonia, nitryl chloride acts as a source of positive chlorine ... 

Incandescent reaction with ethylene + heat, nitrogen + metal chlorides (e.g., chromium trichloride, zirconium tetrachloride, nitryl fluoride (at 200°C)). Incompatible with atmospheric gases,... 

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