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 Carbohydrazide is the chemical compound with the formula OC(N2H3)2. It is a white, water-soluble solid. It decomposes upon melting. A number of carbazides are known where one or more N-H groups are replaced by other substituents. They occur wi ...

: :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

semicarbazone In organic chemistry, a semicarbazone is a derivative of imines formed by a condensation reaction between a ketone or aldehyde and semicarbazide. They are classified as imine derivatives because they are formed from the reaction of an aldehyde o ...

s 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 In organic chemistry, an imine ( or ) is a functional group or organic compound containing a carbon–nitrogen double bond (). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bo ...

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 Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely depo ...

, 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 Furazolidone is a nitrofuran antibacterial agent and monoamine oxidase inhibitor (MAOI). It is marketed by Roberts Laboratories under the brand name Furoxone and by GlaxoSmithKline as Dependal-M. Medical uses Furazolidone has been used in human ...

nitrofurazone Nitrofurazone (INN, trade name Furacin) is an antimicrobial organic compound belonging to the nitrofuran class. It is most commonly used as a topical antibiotic ointment. It is effective against gram-positive bacteria, gram-negative bacteria, a ...

nitrofurantoin Nitrofurantoin is an antibacterial medication used to treat urinary tract infections, but it is not as effective for kidney infections. It is taken by mouth. Common side effects include nausea, loss of appetite, diarrhea, and headaches. Rarely ...

) and related compounds. It is also a product of degradations of the blowing agent

azodicarbonamide Azodicarbonamide, ADCA, ADA, or azo(''bis'')formamide, is a chemical compound with the molecular formula C2H4O2N4. It is a yellow to orange-red, odorless, crystalline powder. It is sometimes called a 'yoga mat' chemical because of its widespread u ...

(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