8444. Semicarbazide Hydrochloride

Nomenclature

CAS number: 563-41-7
Hydrazinecarboxamide monohydrochloride; aminourea hydrochloride; carbamylhydrazine hydrochloride.
CH6ClN3O; mol wt 111.53.
C 10.77%, H 5.42%, Cl 31.79%, N 37.68%, O 14.35%.
NH2NHCONH2.HCl.

Description and references

Prepd by electrolytic reduction of nitrourea with cathodes of copper, nickel, lead, and mercury in hydrochloric acid solution: Ingersoll et al., Org. Synth. 5, 93 (1925). Commercial prepn from hydrazine hydrate, iron carbonyl, and carbon monoxide: Sampson, US 2589289 (1952 to du Pont).

Properties

Prisms from dil alc, dec 175-185°. Freely sol in water with acid reaction. Dissociation consts of free base: Kb at 20° = 29 × 10-11; Ka = 1.6 × 10-11. Very slightly sol in hot alcohol, insol in anhydr ether. Ammonolysis with liquid NH3 gives a 95% yield of the free base; mp 96°: Audrieth, J. Am. Chem. Soc. 52, 1250 (1930).

Derivative

Acetone semicarbazone.
C4H9N3O; mol wt 115.13.
C 41.73%, H 7.88%, N 36.50%, O 13.90%.

Properties

Needles from water, mp 192° (heated stage); mp 188° (open capillary tube).

Use

As a reagent for ketones and aldehydes with which it affords cryst compds having characteristic melting points.