N Nitroso compounds

I. K. O Neill, J. Chen, and H. Bartsch, eds.. Relevance to Human Cancer of N-Nitroso Compounds, Tobacco Smoke andMjcotoxins, lARC Scientific Pubhcation No. 105, International Agency for Research on Cancer, Lyon, Prance, 1991. 

R. A. Scanlan and S. R. Tannenbaum, eds., N-Nitroso Compounds, American Chemical Society, Washington, D.C., 1981. 

W. Lijinsky, Chemist and Biology of N-Nitroso Compounds, Cambridge University Press, Cambridge, U.K., 1992. 

M. C. Archer, S. R. Tannenbaum, andj. S. Wishnok, in E. A. Walker, P. Bogovski, and L. Gticiute, eds.. Environmental N-Nitroso Compounds Mnaljsis andEormation, lARC Scientific PubHcation No. 14, Lyon, France, 1976, pp. 141—145. 

Inhibition of Nitrosamine Formation. Nitrites can react with secondary amines and A/-substituted amides under the acidic conditions of the stomach to form /V-nitrosamines and A/-nitrosamides. These compounds are collectively called N-nitroso compounds. There is strong circumstantial evidence that in vivo A/-nitroso compounds production contributes to the etiology of cancer of the stomach (135,136), esophagus (136,137), and nasopharynx (136,138). Ascorbic acid consumption is negatively correlated with the incidence of these cancers, due to ascorbic acid inhibition of in vivo A/-nitroso compound formation (139). The concentration of A/-nitroso compounds formed in the stomach depends on the nitrate and nitrite intake. 

Synthesis. Almost without exception, azo dyes ate made by diazotization of a primary aromatic amine followed by coupling of the resultant diazonium salt with an electron-rich nucleophile. The diazotization reaction is carried out by treating the primary aromatic amine with nitrous acid, normally generated in situ with hydrochloric acid and sodium nitrite. The nitrous acid nitrosates the amine to generate the N-nitroso compound, which tautomerizes to the diazo hydroxide. 

N-Metal Derivatives N-Nitroso Compounds N-Nitro Compounds Azo Compounds Arenediazoates Arenediazo aryl sulphides Bis-arenediazo oxides Bis-arenediazo sulphides Trizazenes (R=H, -CN, -OH, -NO)... 

Treatment of the heterocycle, 38 (obtained from ethylene-diamine and carbon disulfide), with nitrous acid affords the N-nitroso compound, 39. Reduction with zinc leads to the corre-... 

Substituted amides are converted to NR -substituted amides by treatment with N2O4 to give an N-nitroso compound, followed by treatment of this with a primary amine R NH2. ° Lactams can be converted to ring-expanded lactams if a side chain... 

Ring nitrosation with nitrous acid is normally carried out only with active substrates such as amines and phenols. However, primary aromatic amines give diazonium ions (12-47) when treated with nitrous acid, " and secondary amines tend to give N-nitroso rather than C-nitroso compounds (12-49) hence this reaction is normally limited to phenols and tertiary aromatic amines. Nevertheless secondary aromatic amines can be C-nitrosated in two ways. The N-nitroso compound first obtained can be isomerized to a C-nitroso compound (11-32), or it can be treated with another mole of nitrous acid to give an N,C-dinitroso compound. Also, a successful nitrosation of anisole has been reported, where the solvent was CF3COOH—CH2CI2. " ... 

When secondary amines are treated with nitrous acid, N-nitroso compounds (also called nitrosamines) are formed. The reaction can be accomplished with dialkyl-, diaryl-, or alkylarylamines, and even with mono-N-substituted amides RCONHR -I-HONO RCON(NO)R. Tertiary amines have also been N-nitrosated, but in these cases one group cleaves, so that the product is the nitroso derivative of a secondary amine.The group that cleaves appears as an aldehyde or... 

Nitroso compounds and hydroxylamines can be reduced to amines by the same reagents that reduce nitro compounds (19-41). One example reduces a hydro-xylamine to the amine with CS2 in acetonitrile. N-Nitroso compounds are similarly reduced to hydrazines ... 

Y. and Suzuki, E. in Walker, E.A., Griciute, L., Castegnaro, M. and B8rzs6nyi, M. (eds) N-Nitroso Compounds Analysis, Formation and Occurence lARC Scientific Publications No. 31, International Agency for Research on Cancer, Lyon, 1980 pp. 71-82. 

Loeppky, R.N. Christiansen, R. in "Environmental Aspects of N-Nitroso Compounds" Walker, E.A. Castegnaro, M. Griciute,... 

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