Phenylglyoxal

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Phenylglyoxal
Structure of Phenylglyoxal.png
Phenylglyoxal-3D-balls.png
Names
Preferred IUPAC name
2-Oxo-2-phenylacetaldehyde
Systematic IUPAC name
2-Oxo-2-phenylethanal
Other names
Phenylglyoxal
1-Phenylethanedione
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.012.761 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
RTECS number
  • KM5775180
UNII
Properties
C8H6O2
Molar mass 134.13 g/mol (anhydrous)
Appearanceyellow liquid (anhydrous)
white crystals (hydrate)
Density ? g/cm3
Melting point 76 to 79 °C (169 to 174 °F; 349 to 352 K)(hydrate)
Boiling point 63 to 65 °C (145 to 149 °F; 336 to 338 K)(0.5 mmHg, anhydrous)
forms the hydrate
Solubility in other solventscommon organic solvents
Hazards
Main hazards toxic
R-phrases (outdated) 22-36/37/38
S-phrases (outdated) 22-26-36
Related compounds
Related aldehydes
3,4-Dihydroxyphenylacetaldehyde

Methylglyoxal
Phenylacetaldehyde

Related compounds
benzil
glyoxal
acetophenone
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

Phenylglyoxal is the organic compound with the formula C6H5C(O)C(O)H. It contains both an aldehyde and a ketone functional group. It is yellow liquid when anhydrous but readily forms a colorless crystalline hydrate. It has been used as a reagent to modify the amino acid, arginine. [1] It has also been used to attach chemical payload (probes) to the amino acid citrulline [2] and to peptides/proteins. [3]

Contents

Properties

Like some other aldehydes, phenylglyoxal polymerizes upon standing, as indicated by solidification of the liquid. Upon heating, this polymer "cracks" to give back the yellow aldehyde. Dissolution of phenylglyoxal in water gives crystals of the hydrate:

C6H5C(O)COH + H2O → C6H5C(O)CH(OH)2

Upon heating, the hydrate loses water and regenerates the anhydrous liquid.

Preparation

Phenylglyoxal was first prepared by thermal decomposition of the sulfite derivative of the oxime: [4]

C6H5C(O)CH(NOSO2H) + 2 H2O → C6H5C(O)CHO + NH4HSO4

More conveniently, it can be prepared from methyl benzoate by reaction with KCH2S(O)CH3 to give PhC(O)CH(SCH3)(OH), which is oxidized with copper(II) acetate. [5] Alternatively, it can also be prepared by oxidation of acetophenone with selenium dioxide. [6]

Related Research Articles

Aldehydes, which are generally created by removing a hydrogen from an alcohol, are common in organic chemistry; the most well-known is formaldehyde. As they are frequently strongly scented, many fragrances are or contain aldehydes.

Azide

Azide is the anion with the formula N
3
. It is the conjugate base of hydrazoic acid (HN3). N
3
is a linear anion that is isoelectronic with CO2, NCO, N2O, NO+
2
and NCF. Per valence bond theory, azide can be described by several resonance structures; an important one being . Azide is also a functional group in organic chemistry, RN3.

Hydroxylamine Inorganic compound

Hydroxylamine is an inorganic compound with the formula NH2OH. The pure material is a white, unstable crystalline, hygroscopic compound. However, hydroxylamine is almost always provided and used as an aqueous solution. It is used to prepare oximes, an important functional group. It is also an intermediate in biological nitrification. In biological nitrification, the oxidation of NH3 to hydroxylamine is mediated by the enzyme ammonia monooxygenase (AMO). Hydroxylamine oxidoreductase (HAO) further oxidizes hydroxylamine to nitrite.

Copper(II) nitrate

Copper(II) nitrate, Cu(NO3)2, is an inorganic compound that forms a blue crystalline solid. Anhydrous copper nitrate forms deep blue-green crystals and sublimes in a vacuum at 150-200 °C. Copper nitrate also occurs as five different hydrates, the most common ones being the hemipentahydrate and trihydrate.

Cyanohydrin

A cyanohydrin is a functional group found in organic compounds in which a cyano and a hydroxy group are attached to the same carbon atom. The general formula is R2C(OH)CN, where R is H, alkyl, or aryl. Cyanohydrins are industrially important precursors to carboxylic acids and some amino acids. Cyanohydrins can be formed by the cyanohydrin reaction, which involves treating a ketone or an aldehyde with hydrogen cyanide (HCN) in the presence of excess amounts of sodium cyanide (NaCN) as a catalyst:

Zinc chloride

Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This white salt is hygroscopic and even deliquescent. Samples should therefore be protected from sources of moisture, including the water vapor present in ambient air. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

Acetamide (systematic name: ethanamide) is an organic compound with the formula CH3CONH2. It is the simplest amide derived from acetic acid. It finds some use as a plasticizer and as an industrial solvent. The related compound N,N-dimethylacetamide (DMA) is more widely used, but it is not prepared from acetamide. Acetamide can be considered an intermediate between acetone, which has two methyl (CH3) groups either side of the carbonyl (CO), and urea which has two amide (NH2) groups in those locations.

Peptide synthesis

In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another. Protecting group strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains. Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus (N-terminus). Protein biosynthesis in living organisms occurs in the opposite direction.

Acetylide refers to chemical compounds with the chemical formulas MC≡CH and MC≡CM, where M is a metal. The term is used loosely and can refer to substituted acetylides having the general structure RC≡CM. Acetylides are reagents in organic synthesis. The calcium acetylide commonly called calcium carbide is a major compound of commerce.

Aluminium chloride Chemical compound

Aluminium chloride (AlCl3), also known as aluminium trichloride, describe compounds with the formula AlCl3(H2O)n (n = 0 or 6). They consist of aluminium and chlorine atoms in a 1:3 ratio, and one form also contains six waters of hydration. Both are white solids, but samples are often contaminated with iron(III) chloride, giving a yellow color.

Nickel(II) chloride

Nickel(II) chloride (or just nickel chloride), is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.

Iron(II) chloride

Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in commerce and the laboratory. There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.

Diisobutylaluminium hydride

Diisobutylaluminium hydride (DIBALH, DIBAL, DIBAL-H or DIBAH, DY-bal) is a reducing agent with the formula (i-Bu2AlH)2, where i-Bu represents isobutyl (-CH2CH(CH3)2). This organoaluminium compound was investigated originally as a co-catalyst for the polymerization of alkenes.

The Bouveault–Blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal. It was first reported by Louis Bouveault and Gustave Louis Blanc in 1903. Bouveault and Blanc demonstrated the reduction of ethyl oleate and n-butyl oleate to oleyl alcohol. modified versions of which were subsequently refined and published in Organic Syntheses.

Carbonyldiimidazole

1,1'-Carbonyldiimidazole (CDI) is an organic compound with the molecular formula (C3H3N2)2CO. It is a white crystalline solid. It is often used for the coupling of amino acids for peptide synthesis and as a reagent in organic synthesis.

Glyoxal is an organic compound with the chemical formula OCHCHO. It is the smallest dialdehyde. It is a crystalline solid, white at low temperatures and yellow near the melting point (15 °C). The liquid is yellow, and the vapor is green.

Di-<i>tert</i>-butyl dicarbonate

Di-tert-butyl dicarbonate is a reagent widely used in organic synthesis. Since this compound can be regarded formally as the acid anhydride derived from a tert-butoxycarbonyl (Boc) group, it is commonly referred to as Boc anhydride. This pyrocarbonate reacts with amines to give N-tert-butoxycarbonyl or so-called Boc derivatives. These carbamate derivatives do not behave as amines, which allows certain subsequent transformations to occur that would be incompatible with the amine functional group. The Boc group can later be removed from the amine using moderately strong acids. Thus, Boc serves as a protective group, for instance in solid phase peptide synthesis. Boc-protected amines are unreactive to most bases and nucleophiles, allowing for the use of the fluorenylmethyloxycarbonyl group (Fmoc) as an orthogonal protecting group.

1,2-Ethanedithiol

1,2-Ethanedithiol, also known as EDT, is a colorless liquid with the formula C2H4(SH)2. It has a very characteristic odor which is compared by many people to rotten cabbage. It is a common building block in organic synthesis and an excellent ligand for metal ions.

<i>tert</i>-Butyloxycarbonyl protecting group

The tert-butyloxycarbonyl protecting group or tert-butoxycarbonyl protecting group is a protecting group used in organic synthesis.

Chloramine-T

Chloramine-T is the organic compound with the formula CH3C6H4SO2NClNa. Both the anhydrous salt and its trihydrate are known. Both are white powders. Chloramine-T is used as a reagent in organic synthesis.

References

  1. Kenji Takahashi (1968). "The Reaction of Phenylglyoxal with Arginine Residues in Proteins". J. Biol. Chem. 243 (23): 6171–9. PMID   5723461.
  2. Bicker KL, Subramanian V, Chumanevich AA, Hofseth LJ, Thompson PR (2012). "Seeing citrulline: development of a phenylglyoxal-based probe to visualize protein citrullination". J Am Chem Soc. 134 (41): 17015–8. doi:10.1021/ja308871v. PMC   3572846 . PMID   23030787.
  3. Thompson DA, Ng R, Dawson PE (2016). "Arginine selective reagents for ligation to peptides and proteins". J Pept Sci. 22 (5): 311–9. doi:10.1002/psc.2867. PMID   27005702.
  4. H. von Pechmann (1887). "Zur Spaltung der Isonitrosoverbindungen". Chem. Ber. 20 (2): 2904–2906. doi:10.1002/cber.188702002156.
  5. Mikol, G. J.; Russell, G. A. (1973). "Phenylglyoxal". Organic Syntheses .; Collective Volume, 5, p. 937
  6. Riley, H. A.; Gray, A. R. (1943). "Phenylglyoxal". Organic Syntheses .; Collective Volume, 2, p. 509