Nitrosamine dialkyl

Grosjean, D Atmospheric Chemistry of Toxic Contaminants. 6. Nitrosamines Dialkyl Nitrosamines and Nitrosomorpholine, J. Air Waste Manage. Assoc., 41, 306-311 (1991d). 

In saurer Losung wird Methyl-phenyl-nitrosamin an Blei zu N-Methyl-N-phenyl-hydra-zin reduziert (80% d.Th.)4. Analog verhalten sich Dialkyl-nitrosamine ( — 0,9 V, bis 82% d.Th.) in alkoholischer Salzsaure5. Zur Hcrstellung von N,N-Dimethyl-hydrazin aus dem N-Nitroso-Derivat s.ds. Handb., Bd. X/2, S. 42 (zuN,N-Dialkyl-hydrazinen s.Lit.6). 

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... 

The trialkyltrlazenes are essentially protected diazo-nlum ions. They decompose cleanly and quantitatively to the dlazonlum ions and the corresponding amines over a wide pH range (M). Good kinetic data were obtained over the range of pH 6.9 - 8.3. In more acid solutions, the reactions are too rapid to measure by conventional kinetics. The decomposition reaction is subject to general acid catalysis. Thus, the trialkyltrlazenes will be a useful tool for the study of the reactive intermediates produced by the metabolism of dialkyl-nitrosamines. 

The simplest dialkyl N-nitrosamines are relatively volatile, and airborne N-nitrosamines are to be expected in the vicinity of chemicals which are contaminated with nitrosamines. In situ, formation of N-nitrosamines would be expected to occur if amines were present in close proximity to nitrosating agents such as nitrite, oxides of nitrogen and C-nitro compounds. 

The present work will first discuss our efforts to synthesize a -functionalized dialkyl N-nitrosamines. 

Since 1971, we have been engaged in the synthesis of g-substituted dialkyl N-nitrosamines, namely -hydroxy N-nitrosamines. Because of the presumed high reactivity of these alcohols, it seemed desirable to have them in a stabilized form, e.g. as esters. In 1970 Franck and his group reported a method to convert tertiary amines into dialkyInitrosamines in the presence of 2-nitropropane, cuprous ion and oxygen 9). If the amine is substituted with different alkyl groups, these groups are cleaved statistically (Eq. 1). 

In 1972, Eiter and his group reported the synthesis of a-alkoxy dialkyl N-nitrosamines (11),which can be obtained easily in 20-50 g quantities. This synthetic scheme works well when formaldehyde was used. In those cases when higher aliphatic aldehydes are used (e.g. acetaldehyde), the yields decreased to 3-5%. The a -alkoxy dialkyInitrosamines always contained the trimeric paraldehyde as impurity. When acetaldehyde and... 

Proposed riechanism for the Nucleophilic Displacement of Acetate in a -Acetoxy dialkyl-nitrosamines... 

Kerklaan, P, Mohn, G. Bouter, S. (1981) Comparison of the mutagenic activity of dialkyl-nitrosamines in animal-mediated and in vitro assays using an Escherichia coli indicator. Carcinogenesis, 2, 909-914... 

Although 3-amino-l,2,4-thiadiazoles (e.g. the 5-phenyl homolog) fail to yield nitrosamines under the usual conditions,126 5-nitrosamines are well known.81, 5,190,191 Thus, 3-alkoxy-,8 3-alkylthio-,85 3-dialkyl-amino-,87 and 3-alkylsulfonyl-5-amino-86 (243) as well as 3-aryl-5-arylamino-l,2,4-thiadiazoles,74 on treatment with the calculated quantity of sodium nitrite in dilute mineral acid, or concentrated formic acid, yield crystalline nitrosamines (244). Their unusual stability has permitted a close study of their formation and properties. 170 Their positive Liebermann reaction85,87,170 and the results of their methylation (outlined in the reaction scheme) show that nitro-sation occurs in the side-chain and not in the nucleus.170... 

Gas chromatography has been applied to the determination of a wide range of organic compounds in trade effluents including the following types of compounds which are reviewed in Table 15.15 aromatic hydrocarbons, carboxylic acids aldehydes, non ionic surfactants (alkyl ethoxylated type) phenols monosaccharides chlorinated aliphatics and haloforms polychlorobiphenyls chlorlignosulphonates aliphatic and aromatic amines benzidine chloroanilines chloronitroanilines nitrocompounds nitrosamines dimethylformamide diethanolamine nitriloacetic acid pyridine pyridazinones substituted pyrrolidones alkyl hydantoins alkyl sulphides dialkyl suphides dithiocaibamate insecticides triazine herbicides and miscellaneous organic compounds. 

For the estimation of volatile dialkyl nitrosamines and A-nitrosopiperidine, A-nitrosopyrrolidine and A-nitrosomorpholine, ION sulphuric acid was added to the sample which was then extracted with redistilled dichloromethane. 1.5m sodium hydroxide was added to the combined extract. After separation, the organic layer was dried over sodium sulphate and evaporated to 2.5mL at 46°C on a water bath. Hexane was added, and evaporation continued to about 250pL. Ahquots of 5pL were analysed for volatile nitrosamines using gas chromatography. 

We examined the thermal decomposition of a number of nitramines in dilute solution and in the melt phase. The nitramines included acyclic dialkyl mononitramines, where the dialkyls were methyl, ethyl, propyl and isopropyl cyclic mononitramines (N-nitro-pipeiidine and N-nitropyrrolidine) and cycle multifunctional nitramines (N-dinitropiperazhe l,3-dinitro-l,3-diazacyclo-pentane l,3-dinitro-l,3-diazacycbhexane RDX and HMX). For all nitramines, the predominant condensed-phase product was the nitrosamine though the amount formed depending on the nitramine and the phase of the thermolysis. The common trigger in the decompositions was N-N02 ho mo lysis, but the fate of the resultant amine radical depended on the phase. In solution the radical was stabilized sufficiently so that it resisted further decomposition and, instead, reacted with NO to form nitrosamine. In vapor or condensed phase, the amine radical underwent further reaction therefore,... 

The electrochemical reduction of A-nitrosamines in acid solution is a convenient and general synthetic route to dialkylated, unsymmetrical hydrazines [210]. Quite a few nitrosamines were reduced to hydrazines in the classic period, but later investigations [211,212] also indicate a continued interest in the reaction. 

Langenbach R. 1986. Mutagenic activity and structure-activity relationships of short-chain dialkyl N-nitrosamines in a hamster hepatocyte V79 cell-mediated system. Mutat Res 163 303-311. 

In the rubber industiy, vidcanization accelerators based on secondary amines may form carcinogenic nitrosamines. This risk can be avoided by basing productirMi on primary or tertiary amines or using zinc dialkyl phosphates (manufacturer Rhein-Chemie). 

Symmetrical dialkyl-nitrosamines Methyl alkyl nitrosamines Cyclic nitrosamines Aryl-alkyl and diaryl nitrosamines... 

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