Nitroamides, decomposition

Although this reaction does not lead to an alkanediazonium ion, it is obvious that it is another method that is closely related to the deamination pathways discussed in this section. The azoxytoluenesulfonate method is related to the use of N-nitroamides as a source for carbocations because the leaving group is also nitrous oxide (7-10). The A -nitroamide decomposition was used extensively by White and coworkers in the 1960 s and 1970 s (see White and Grisley, 1961 White et al., 1973 White and Field, 1975, and literature cited there). N-Nitro carbamates (7.25, R = OR") can also be used. 

Nitroamide is strongly acidic, a white crystalline substance, melting at 72-73° with decomposition, readily soluble in water, alcohol, and ether, and insoluble in petroleum ether. It explodes on contact with concentrated sulfuric acid. The pure material decomposes slowly on standing, forming nitrous oxide and water it cannot be preserved for more than a few days. When an aqueous solution of nitroamide is warmed, gas bubbles begin to... 

The thermal decompositions of A-nitroamides and A -nitrocarbamates were found to be first order . Arrhenius parameters are shown in Table 31. In both cases the rates of decomposition increase with increasing size of the alkyl substituent, but carbamate derivatives were more stable than amides. In the case of nitrocarbamates, resonance stabilization in the ground state leads to an increase in the energy of activation leading to decomposition via a 4-centred transition state, viz. 

The corresponding iV-nitroamides (31) decompose under similar conditions to yield similar products (equation 113). The nitro-amides are useful in that the critical intermediate 32 can be prepared by an independent path—the reaction of a nitroamine salt (33) with an acyl halide, a reaction that can be studied at much lower temperatures than are feasible for the decomposition of the nitroamides... 

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