Amination with Nitrogen Oxides

Ambient Air. Hanst, et al (42) showed that dimethylamine could react with nitrogen oxides in the atmosphere to form N-nitrosodimethylamine. Fine, et al (39) in studies in New York City, Boston and upstate New Jersey, found little evidence to suggest that NDMA or other N-nitroso comf>ounds were being formed in the atmosphere, even in the neighborhood of amine factories. NDMA was found sporadically, in only 3 out of 40 sites. 

However, the production of the />-phenylenediamine [106-50-3] intermediate is more complex, because it involves the diazotization and coupling of aniline [65-53-3]. Aniline reacts with nitrogen oxides, produced via the oxidation of ammonia, to form 1,3-diphenyltriazene [136-35-6] in the process used by Du Pont (208,209) (see Amines, aromatic-aniline and its derivatives). In the Akzo process a metal nitrite salt and acid in water is used (210). The triazene rearranges in the presence of acid and an excess of aniline to form predominately the p-aminoazobenzene [60-09-3] and a small amount of the ortho isomer, 0-aminoazobenzene [2835-58-7]. The mixture of isomers is catalytically reduced to the respective diamines, and they are then separated from the aniline, which is recycled (208,209). The 0-phenylenedi amine [95-54-5] is used in the manufacture of herbicides (see Amines, aromatic-phenylenediamines). 

HAZARD RISK Flammable liquid fire hazard when exposed to heat, flame, sparks, friction or oxidizing materials incompatible with strong oxidziers, active metals such as sodium, potassium and zinc, rust, halogens and amines vapor ignites on contact with fluorine potentially explosive when heated in contact with rust, iron potentially explosive reaction in contact with nitrogen oxide explodes on contact with permanganic acid decomposition emits toxic fumes of SOx NFPA code H 3 F 3 R 0. 

We should note here that there is a need to reduce the use of accelerators based on secondary amines, which can react with nitrogen oxides to form suspected carcinogenic nitrosamines. This is especially a problem... 

At the pH of beer ammonia and the other volatile amines in beer (Table 22.18) will be present as their non-volatile salts. Ammonia is the most abundant volatile nitrogenous constituent the mean value in a range of US beers was 14 6 ppm (3-33 ppm) compared with 21 3 ppm (0-33 ppm) in imported beers [93]. At the low concentrations found, the volatile amines will have little influence on the flavour of beer. Dimethylamine is commonly the major constituent. Secondary amines such as dimethylamine react with nitrogen oxides to form carcinogenic A -nitrosamines ... 

The occurrence and determination of aliphatic amines have received a great deal of attention in recent years [42-44]. These foul-smelling compounds have been found in a number of ambient environments [45-47] and become a source of serious social and psychological problems. They are also involved in nitrosamine synthesis in air [48], because methylamines react with nitrogen oxides (NO ) and O2. 

Coordination Compounds. Osmium in oxidation states from +2 to +8 forms a wide range of complexes with nitrogen ligands. Amine... 

The most general method for synthesis of cyclic enamines is the oxidation of tertiary amines with mercuric acetate, which has been investigated primarily by Leonard 111-116) and applied in numerous examples of structural investigation and in syntheses of alkaloids 102,117-121). The requirement of a tram-coplanar arrangement of an a proton and mercury complexed on nitrogen, in the optimum transition state, confers valuable selectivity to the reaction. It may thus be used as a kinetic probe for stereochemistry as well as for the formation of specific enamine isomers. 

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