Alkyl nitrites compounds

Aliphatic nitro compounds. These are isomeric with the alkyl nitrites and may be prepared from the alkyl halide and silver nitrite, for example C,H,aBr + AgNOj — C Hj NO + AgBr... 

In addition to CuCfi, some other compounds such as Cu(OAc)2, Cu(N03)2-FeCl.i, dichromate, HNO3, potassium peroxodisulfate, and Mn02 are used as oxidants of Pd(0). Also heteropoly acid salts comtaining P, Mo, V, Si, and Ge are used with PdS04 as the redox system[2]. Organic oxidants such as benzo-quinone (BQ), hydrogen peroxide and some organic peroxides are used for oxidation. Alkyl nitrites are unique oxidants which are used in some industrial... 

An important side reaction in all free-radical nitrations is reaction 10, in which unstable alkyl nitrites are formed (eq. 10). They decompose to form nitric oxide and alkoxy radicals (eq. 11) which form oxygenated compounds and low molecular weight alkyl radicals which can form low molecular weight nitroparaffins by reactions 7 or 9. The oxygenated hydrocarbons often react further to produce even lighter oxygenated products, carbon oxides, and water. 

Under alkaline conditions, alkyl nitrites nitrosate imidazoles which possess a free NH group in the 4-position (70AHC(12)103). Nitrosation of 3,5-dimethylpyrazole gives the 4-diazonium salt by further reaction of the nitroso compound with more NO". 5-Pyrazolinones are often nitrosated readily at the 4-position. 3-Alkyl-5-acetamidoisothiazoles undergo 4-nitrosation. 

Carbons adjacent to a Z group (as defined on p. 548) can be nitrosated with nitrous acid or alkyl nitrites. The initial product is the C-nitroso compound, but these are stable only when there is no tautomerizable hydrogen. When there is, the product is the more stable oxime. The situation is analogous to that with azo compounds and hydrazones (12-7). The mechanism is similar to that in 12-7 R—H —> R + N=0 — R—N=0. The attacking species is either NO or a carrier of it. When the substrate is a simple ketone, the mechanism goes through the enol (as in halogenation 12-4) ... 

Other compounds with nitrogen-nitrogen bonds have been used instead of diazonium salts. Among these are N-nitroso amides [ArN(NO)COR], triazenes, and azo compounds. Still another method involves treatment of an aromatic primary amine directly with an alkyl nitrite in an aromatic substrate as solvent. ... 

Nitrous acid or alkyl nitrites react with a number of nitrogen compounds to yield tetrazoles. For example, hydrazidines (87), which can be prepared in situ from the corresponding iminoesters, react with nitrous acid or its derivatives to give 1-substituted tetrazoles (88).150-152 This reaction (Eq. 17), is one of the most extensively used methods for the synthesis of... 

The reaction of alkyl halides with metal nitrites is one of the most important methods for the preparation of nitroalkanes. As a metal nitrite, silver nitrite (Victor-Meyer reaction), potassium nitrite, or sodium nitrite (Kornblum reaction) have been frequently used. The products are usually a mixture of nitroalkanes and alkyl nitrites, which are readily separated by distillation (Eq. 2.47). The synthesis of nitro compounds by this process is well documented in the reviews, and some typical cases are listed in Table 2.3.92a Primary and secondary alkyl iodides and bromides as well as sulfonate esters give the corresponding nitro compounds in 50-70% yields on treatment with NaN02 in DMF or DMSO. Some of them are described precisely in vol 4 of Organic Synthesis. For example, 1,4-dinitrobutane is prepared in 41 -46% yield by the reaction of 1,4-diiodobutane with silver nitrite in diethyl ether.92b 1-Nitrooctane is prepared by the reaction with silver nitrite in 75-80% yield. The reaction of silver nitrite with secondary halides gives yields of nitroalkanes of about 15%, whereas with tertiary halides the yields are 0-5%.92c Ethyl a-nitrobutyrate is prepared by the reaction of ethyl a-bromobutyrate in 68-75% yield with sodium nitrite in DMF.92d Sodium nitrite is considerably more soluble in DMSO than in DMF as a consequence, with DMSO, much more concentrated solutions can be employed and this makes shorter reaction times possible.926... 

Condensations with alkyl nitrites and nitrates, however, are not so generally applicable as the true ethyl acetoacetate reaction, and the possibility is not excluded that they proceed in another way compounds with mobile hydrogen might first he added to the inorganic part of the ester by means of an aldol condensation. The fact that fluorene, which contains no active double bond at all, combines with ethyl nitrate (as well as with ethyl oxalate) and sodium ethoxide in the same way, yielding oci-nitrofluorene, seems to support this second theory (W. Wislicenus). 

Many alkyl nitrites are thermally unstable and may readily decompose or explode on heating [1], Methyl nitrite explodes more violently than ethyl nitrite [2], Lower alkyl nitrites have been known to decompose and burst the container, even in refrigerated storage [3], Individually indexed compounds are f Butyl nitrite, 1658 f fert-Butyl nitrite, 1659... 

Treatment of alkyl nitrites with arylsulfinic acids 194 generates the unstable nitroso compounds 195, which, in the presence of dienes, are trapped as cycloadducts 196 (equation 109)102. 

In a paper pnblished in the early 1950s Touster found that sodio derivatives of many alkyl-substituted heteroaromatic compounds or of allyl-substituted benzenes 30 can be oximated with alkyl nitrites in refluxing anhydrous liquid ammonia at atmospheric pressure... 

Subsequently, Kato and Goto have reported the synthesis of 2- and 4-pyridinecarbox-aldoximes from 2- and 4-picoline with potassium amide and amyl nitrite in liquid ammonia at — 33°C, although they failed to obtain either of these oximes when the reaction was carried ont with sodium amide in liquid ammonia at room temperature in a sealed tube. Finally, in 1964, aUcyl-substituted heteroaromatic compounds and allyl-substituted benzenes were oximated in liquid ammonia at —33 °C with sodamide and an alkyl nitrite . 

When olefins are treated with N204 in an ether, ester, or alkane as solvent, vtc-dinitro compounds and 3-nitro alkyl nitrites are produced.803 The reaction can be successfully performed with all kinds of olefins and acetylenes. Generally, both products are produced. The dinitro compound is usually stable, but the ester is quite reactive. Upon addition of water or alcohol it is hydrolyzed to a 3-nitro alcohol. If oxygen is added, it is oxidized to a 3-nitro alkyl nitrate or an a-nitro aldehyde or ketone. 

Irradiation of octyl nitrite has already been described Kabasakalian et al. have also studied the behavior of its lower homologs.24 It was observed that primary alkyl nitrites with more than four carbon atoms in a chain produced essentially identical yields (37 to 45%) of nitroso dimer formed by the Barton reaction until the minimum straight-chain length of four carbon atoms was reached. Butyl nitrite underwent internal hydrogen abstraction in poor yield. This is the result of a more difficult abstraction of a primary hydrogen as compared to a secondary hydrogen atom available in compounds with longer chains. Reaction paths 2 and 4 predominated to afford 1-butanol and butanal as the major products. 

Method (d), based on UV photolysis-TEA detection, seemed to give positive response to alkyl nitrites and C-nitroso compounds. In this respect, it is less specific than the preceding two HX-catalyzed denitrosation techniques, which give either negligible or no response for such compounds. Data on the actual use of the methods mentioned in Table 2 for the determination of NOC in foods is, however, limited. 

Alkyl methyl ketones undergo nitrosation at the reactive methylene group when treated with nitrous acid or an alkyl nitrite [Method (fi)]. The presence of hydrogen on the a-carbon permits tautomeric rearrangement to the oxime of a 1,2-dicarbonyl compound. Acidic hydrolysis of the oxime, which is best carried out in the presence of a hydroxylamine acceptor such as laevulinic acid,143 affords a further useful route to the 1,2-dicarbonyl system. 

MRH values calculated for 16 combinations, largely with oxidants, are given. See Other ALKYL NITRITES, N—O COMPOUNDS... 

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