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

urea Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important ...

Synthesis

The compound prepared by treating

with

hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazin ...

:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. . :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

Semicarbazide is frequently reacted with

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group ...

s and

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bon ...

s to produce semicarbazones via a

condensation reaction In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a ...

. This is an example of imine formation resulting from the reaction of a primary amine with a

carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a ...

. The reaction is useful because semicarbazones, like

oxime In organic chemistry, an oxime is a organic compound belonging to the imines, with the general formula , where R is an organic side-chain and R’ may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substitu ...

s and 2,4-DNPs, typically have high melting points and crystallize, facilitating purification or identification of reaction products.

Properties

Semicarbazide products (semicarbazones and thiosemicarbazones) are known to have an activity of

antiviral Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do no ...

, antiinfective and antineoplastic through binding to

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

in cells.

Uses, occurrence, detection

Semicarbazide is used in preparing

pharmaceuticals A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and ...

including

nitrofuran Nitrofurans are a class of drugs typically used as antibiotics or antimicrobials. The defining structural component is a furan Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one ...

antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

s ( furazolidone, nitrofurazone, nitrofurantoin) and related compounds. It is also a product of degradations of the blowing agent azodicarbonamide (ADC). Semicarbazide forms in heat-treated flour containing ADC as well as breads made from ADC-treated flour. Semicarbazide is used as a detection reagent in

thin layer chromatography Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. Thin-layer chromatography is performed on a sheet of an inert substrate such as glass, plastic, or aluminium foil, which is coated with a t ...

(TLC). Semicarbazide stains α-keto acids on the TLC plate, which can then be viewed under

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiati ...

light.

References

External links