Nitrosamine, formation reversibility

Used in combination with other accelerators, the dithiophosphates reduce the risk of bloom and the formation of nitrosamines. Generally reversion stability is improved. The copper dithiophosphate will cause discolouration and contact staining. 

Experiment.—In order to show that this formation of aromatic nitrosamines is reversible, boil a small amount of the pure compound just prepared in xylene and hold a piece of moist potassium iodide-starch paper over the mouth of the tube. 

A feature of the acid-catalysed nitrosation of some heterocyclic secondary amines and their 1-oxide derivatives is the reversibility of nitrosamine formation as shown in (10). Apparently these nitrosamines readily undergo denitro-sation (for a discussion of nitrosamine reactions see Section 7). In some cases... 

The nitrosation of secondary amines is reversible in acid solution, so A-nitrosamines may be hydrolized at low pH. Such hydrolysis is especially important for diaryl nitrosamines but also significant for aryl akyl nitrosamines. The NO liberated in the hydrolysis may react with the reduction product from the A-nitrosamine, the unsymmetrical hydrazine, with formation of amine and N2O [213,214] ... 

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