Semicarbazide

Structural formula
General
Surname	Semicarbazide
other names	N- amino urea Carbamic acid hydrazide Carbamyl hydrazine
Molecular formula	CH 5 N 3 O
Brief description	colorless crystals
External identifiers / databases
CAS number 57-56-7 (semicarbazide) 563-41-7 (hydrochloride) EC number 200-339-6 ECHA InfoCard 100,000,308 PubChem 5196 ChemSpider 5008 Wikidata Q417535
properties
Molar mass	75.08 g mol −1
Physical state	firmly
Melting point	96 ° C
solubility	easily soluble in ethanol and water slightly soluble in diethyl ether and benzene
safety instructions
GHS labeling of hazardous substances Hydrochloride danger H and P phrases H: 301-315-319 P: 260-302 + 352-305 + 351 + 338-308 + 310
Toxicological data	176 mg kg −1 ( LD 50 ,  mouse ,  oral ) 40 mg kg −1 ( TD Lo ,  human ,  iv )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Semicarbazide , also called N- aminourea , is a chemical compound and a derivative of urea . The solid, easily water-soluble substance was previously often used to characterize carbonyl compounds , since the reaction products ( semicarbazones ) crystallize well and usually have sharp melting points.

Presentation, properties and reactions

N- amino urea is produced by reacting potassium cyanate with hydrazine hydrochloride or hydrazine hydrate with urea

${\displaystyle \mathrm {H_{2}N{\text{-}}NH_{2}\ +H_{2}N{\text{-}}CO{\text{-}}NH_{2}} }$ ${\displaystyle \mathrm {\longrightarrow H_{2}N{\text{-}}CO{\text{-}}NH{\text{-}}NH_{2}\ +NH_{3}} }$

Hydrazine and urea react to form semicarbazide and ammonia .

The colorless, crystalline compound dissolves easily in ethanol and water, but little in ether or benzene. When heated, semicarbazide decomposes to form hydrazine and hydrazodicarbonamide . With mineral acids, aminourea forms well crystallizing salts; with aldehydes and ketones , crystalline semicarbazones are formed with elimination of water. Semicarbazide is mainly used in the form of the stable hydrochloride .

Individual evidence

1. ↑ ^{a b c d e} Wissenschaft-Online-Lexika: Entry on "Semicarbazid" in the Lexikon der Chemie. Retrieved June 9, 2010.
2. ↑ ^{a b} Entry on semicarbazide hydrochloride in the GESTIS substance database of the IFA , accessed on February 8, 2018(JavaScript required) .
3. ↑ ^{a b} E. H. JENNEY, CC PFEIFFER: The convulsant effect of hydrazides and the antidotal effect of anticonvulsants and metabolites. In: The Journal of pharmacology and experimental therapeutics. Vol. 122, Number 1, January 1958, pp. 110-123, PMID 13502836 .
4. ↑ ^{a b} Entry on semicarbazide in the ChemIDplus database of the United States National Library of Medicine (NLM) .
5. ↑ Science-Online-Lexika: Entry on "Semicarbazone" in the Lexikon der Chemie. Retrieved June 9, 2010.