Triazenes, from Grignard reagents

The synthesis and mechanism of formation of a triazene from an arenediazonium ion and an amine with one or two aliphatic substituents (see Scheme 13-1, R = alkyl, R = H or alkyl) will be discussed in Section 13.2. Here we will briefly mention Dimroth s method (1903, 1905 a) for synthesis of wholly aliphatic triazenes (Scheme 13-6, R and R = alkyl). Dimroth obtained these by the action of Grignard reagents on alkyl azides followed by isolation via copper(i) salts. The Grignard method can also be applied for the synthesis of triazenes with an aromatic substituent by using an aryl azide. 

This procedure represents the most convenient synthesis of l-methyl-3-/>-tolyltriazene. Triazenes with more complex alkyl groups may be prepared from the corresponding amine2 or Grignard reagent.3... 

Hydrolysis of the triazenes so obtained from aromatic Grignard reagents to give aromatic amines may be carried out with either aqueous formic acid or... 

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