1911 Encyclopædia Britannica/Azoximes

AZOXIMES (furo [a.b.] diazoles), a class of organic compounds which contain the ring system HC＝ N 
 N ＝CH O. They may be prepared by converting nitriles into amidoximes by the action of hydroxylamine, the amidoximes so formed being then acylated by acid chlorides or anhydrides. From these acyl derivatives the elements of water are removed, either by simple heating or by boiling their aqueous solution; this elimination is accompanied by the formation of the azoxime ring. Thus

C6H5CN

NH2OH  ⟶

C6H5·C

N·OH   NH2

boil with   ⟶   propionic anhydride

[

C6H5C

N·O·COC2H5   NH2

]

⟶ C6H5·C

N·O   N

C·C2H5.

Azoximes can also be produced from α-benzil dioxime by the “Beckmann” change. Most of the azoximes are very volatile substances, sublime readily, and are easily soluble in water, alcohol and benzene.

For detailed descriptions, see F. Tiemann (Ber., 1885, 18, p. 1059), O. Schulz (Ber., 1885, 18, pp. 1084, 2459), and G. Müller (Ber., 1886, 19, p. 1492); also Annual Reports of the Chemical Society).