2-Nitrosodiphenylamines

V-Nitrosodiphenylamine can act as a nitrosating agent for other amines with all the consequences thereof (see A/-Nitrosamines). 

In explosives, diphenylamine stabilizes cellulose nitrate by reacting with nitrogen oxides (see Explosives and propellants). The products formed include /V-nitrosodiphenylamine and mono andpolynitro derivatives. 

Rubber Chemicals. Sodium nitrite is an important raw material in the manufacture of mbber processing chemicals. Accelerators, retarders, antioxidants (qv), and antiozonants (qv) are the types of compounds made using sodium nitrite. Accelerators, eg, thiuram [137-26-8J, greatly increase the rate of vulcaniza tion and lead to marked improvement in mbber quaUty. Retarders, on the other hand (eg, /V-nitrosodiphenylamine [156-10-5]) delay the onset of vulcanization but do not inhibit the subsequent process rate. Antioxidants and antiozonants, sometimes referred to as antidegradants, serve to slow the rate of oxidation by acting as chain stoppers, transfer agents, and peroxide decomposers. A commonly used antioxidant is A/,AT-disubstituted Nphenylenediamine which can employ sodium nitrite in its manufacture (see Rubber chemicals). 

Amino substituents also behave normally with electrophiles, being acylated and converted to benzylidene derivatives. A-Amino groups have also been converted to benzylidene derivatives and are removed on treatment with A-nitrosodiphenylamine (79JHC249). 

The result of preventive measures is shown in Table VIII. In a tire and tube factory nitrosodiphenylamine (NDPhA) was substituted by cyclohexylthiophthalimid (PVI) to remove the major nitrosating agent. 

Dinitrophenol 4,6 -Dinitro-o -cresol V-Nitrosodimethylamine V-Nitrosodiphenylamine V-Nitrosodi-n-propylamine Pentachlorophenol Phenol... 

Amination of aromatic nitro compounds is a very important process in both industry and laboratory. A simple synthesis of 4-aminodiphenyl amine (4-ADPA) has been achieved by utilizing a nucleophilic aromatic substitution. 4-ADPA is a key intermediate in the rubber chemical family of antioxidants. By means of a nucleophibc attack of the anilide anion on a nitrobenzene, a o-complex is formed first, which is then converted into 4-nitrosodiphenylamine and 4-nitrodiphenylamine by intra- and intermolecular oxidation. Catalytic hydrogenation finally affords 4-ADPA. Azobenzene, which is formed as a by-product, can be hydrogenated to aniline and thus recycled into the process. Switching this new atom-economy route allows for a dramatic reduction of chemical waste (Scheme 9.9).73 The United States Environmental Protection Agency gave the Green Chemistry Award for this process in 1998.74... 

N-Nitroso compounds occur in many operations in the rubber industry. Some nitrosamines (nitrosodiphenylamine, N-N-dinitrosopentamethylenetetramine, polymerized N-nitroso 2,2,4-trimethyl-l,2-dihydroquinoline and N-methyl-N-4-dinitroso aniline) are used as organic accelerators and antioxidants in the production of rubber and often the products are found to be contaminated with such compounds [19]. 

Various nonvolatile nitrosamines were analyzed using HPLC-UV photolysis-CLD. This was applied for determination of V-nitrosamides in dried squid589 and N-nitrosodiphenylamine (278c) in treated apples590. 

C-polyaromatic hydrocarbons deoxyribonucleic acid environmental Protection Agency peroxy nitric acid nitric acid lipopolysaccharide nitrogen/Carbon isocynate radical N-nitrosodibuty lamine N-nitrosodiethylamine N-nitrosodiethanolamine N-nitrosodimethylamine N-nitrosodiphenylamine N-nitrosoethylmethylamine... 

The extent of formation of these NOC depends upon the presence of nitrogen oxides present in the atmosphere during the manufacturing cycle. The major contaminants are NDMA, A-nitrosodiethylamine (NDEA), A-nitrosopyrrolidine (NPYR), NMOR, A-nitrosodiphenylamine (NDPhA), A-nitrosopiperidine (NPIP) and A-nitrosodibutylamine (NDBA)68. NMOR was found in the hot process areas NDMA occurred in tube production areas in which NDPhA was being used as retarder and tetramethylthiuram disulphide as an accelerator. Figure 12 shows a proposed reaction scheme of formation of NOC in the rubber industry and subsequent exposure67. 

Montmorillonite KIO clay and its various cation-exchanged forms have been found to promote the formation of an unexpected product, p-nitrosodiphenylamine, from iV-phenylhydroxylamine, rather than the typical Bamberger products. A Bamberger rearrangement has been shown to occur during the metabolism of 2,4,6-trinitrotoluene... 

---