FURAZANES (furo—a.a'—diazoles)  , organic compounds obtained by heating the glyoximes (dioximes of ortho-diketones) with alkalis or ammonia . Dimethylfurazane is prepared by heating dimethylglyoxime with excess of ammonia for six hours at 165° C . (L . Wolff, Ber., 1895, 28, p . 70) . It is a liquid (at ordinary temperature) which boils at 156° C . (744 mm.) . Potassium permanganate oxidizes it first to methylfurazanecarboxylic acid and then to furazanedicarboxylic acid . Methylethylfurazane and diphenylfurazane are also known . By warming oxyfurazane acetic acid with excess of potassium permanganate to roo° C. oxyfurazanecarboxylic acid is obtained (A . Hantzsch and J . Urbahn, Ber., 1895, 28, p .

764) . It crystallizes in prisms, which melt at 175° C . Furazanecarboxylic acid is prepared by the

action of a large excess of potassium permanganate on a hot solution of furazanepropionic acid . It melts at 107° C., and dissolves in caustic soda, with a deep yellow colour and formation of nitrosocyanacetic acid (L . Wolff and P . F . Ganz, Ber., 1891, 24, p . 1167) . Furoxane is an oxide of furazane, considered by H . Wieland to be identical with glyoxime peroxide; Kekule's dibromnitroacetonitrile is dibromfuroxane . The formulae of the compounds above mentioned are: HC: N CH3•C: N>0 HC : N>O H:N CHa C: N HO2C•C: N Furazane . Dimethyl- Furazane- furazane. carboxylic acid .