Semicarbazide

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Semicarbazide
Skeletal formula of semicarbazide
Ball-and-stick model of the semicarbazide molecule
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.000.308
KEGG
Properties
H2NNHC(=O)NH2
Molar mass 75.08 g/mol
Melting point 96 °C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea.

Synthesis[edit]

The compound prepared by treating urea with hydrazine:[1]

OC(NH2)2 + N2H4 → OC(NH2)(N2H3) + NH3

A further reaction can occur to give carbohydrazide:

OC(NH2)(N2H3) + N2H4 → OC(N2H3)2 + NH3

Derivatives[edit]

Semicarbazide is frequently reacted with aldehydes and ketones to produce semicarbazones via a condensation reaction. This is an example of imine formation resulting from the reaction of a primary amine with a carbonyl group. The reaction is useful because semicarbazones, like oximes and 2,4-DNPs, typically have high melting points and crystallize, facilitating purification or identification of reaction products.[2]

Thiosemicarbazide is the analogous compound with sulfur atom in place of oxygen atom,[3] with 4-Methyl-3-thiosemicarbazide being a simple example.

Properties[edit]

Semicarbazide products (semicarbazones and thiosemicarbazones) are known to have an activity of antiviral, antiinfective and antineoplastic through binding to copper or iron in cells.

Uses[edit]

Semicarbazide is used in preparing pharmaceuticals including: nitrofuran antibacterials (furazolidone, nitrofurazone, nitrofurantoin) and dizatrifone.

Semicarbazide is used as a detection reagent in thin layer chromatography (TLC). Semicarbazide stains α-keto acids on the TLC plate, which must then be viewed under ultraviolet light to see the results.

Occurrence[edit]

Semicarbazide has been shown to be formed in heat-treated flour containing azodicarbonamide as well as breads made from azodicarbonamide-treated flour.[4]

Structures[edit]

See also[edit]

References[edit]

  1. ^ Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a13_177.
  2. ^ John McMurry (1984). Organic Chemistry. Brooks/Cole. p. 676. 
  3. ^ . PubChem https://pubchem.ncbi.nlm.nih.gov/compound/2723789.  Missing or empty |title= (help)
  4. ^ Becalski, Adam; Lau, Benjamin; Lewis, David; Seaman, Stephen (2004). "Semicarbazide Formation in Azodicarbonamide-Treated Flour:  A Model Study". J. Agric. Food Chem. 52 (18): 5730–4. PMID 15373416. doi:10.1021/jf0495385. 

External links[edit]