1911 Encyclopædia Britannica/Furazanes

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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 methylfurazane-carboxylic acid and then to furazanedicarboxylic acid. Methyl-ethylfurazane and diphenylfurazane are also known. By warming oxyfurazane acetic acid with excess of potassium permanganate to 100° 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; Kekulés dibromnitroacetonitrile is dibromfuroxane.

The formulae of the compounds above mentioned are:

HC. :N CH3⋅C. :N HO2CC. :N N..·O·N.
Furazane.  Dimethyl-
carboxylic acid.