1911 Encyclopædia Britannica/Azoximes

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AZOXIMES (furo [a.b.] diazoles), a class of organic compounds which contain the ring system

HC = N 
 N = CH

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


C6H5·CLangleIT.svg N·OH
boil with

propionic anhydride
[ C6H5C LangleIT.svg N·O·COC2H5
] C6H5·C LangleIT.svg N·O
RangleIB.svg 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).