AZOXIMES (furo [a.b.] diazoles)  , a class of organic compounds which contain the ring system NC Cg >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 NH2OH boil with CaH6CN-->CsHs•C'NH2H —~ propioaic anhydride [CGH6C(.COC2H6] -'CBH5.G\N O>C C2Hs' Azoximes can also be produced from a-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, i8, p . 1059), O . Schulz (Ber., 1885, 18, pp . 1084, 2459), and G . Muller (Ber.,i886,19, p.1492); also Annual Reports of the Chemical Society) .