Hydrazine salts melting points

The process of this invention is based upon the discovery that phthalyl hydrazides, sparingly soluble and relatively nonvolatile acids of high melting point, combine with hydrazine to form well-defined nonhydrated salts. 

Allophanyl hydrazide is a white, crystalline, nonhygro-scopic compound which melts at 166° with decomposition. It is soluble in water, methanol, and ethanol (at their boiling points) to the extents of 14, 3, and 1.4 g./lOO ml. of solvent, respectively. It is a weak base, KB = 10-n. Melting points and formulas of typical salts are tabulated below. The compound is thermally unstable when heated at 110° for an extended period of time. As a typical hydrazine derivative, allophanyl hydrazide forms allophanyl hydrazones with carbonyl compounds. Among these, the water-insoluble benzaldehyde derivative (m.p. 208 to 209°) is easily prepared. Allophanyl hydrazide can also be treated with nitrous acid to give the water-insoluble azide, NH2CONHCON3, melting with decomposition at 193°. 

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