Terephthalaldehyde

Last updated
Terephthalaldehyde
Terephthalaldehyde.png
Names
Other names
1,4-Benzenedialdehyde
1,4-Diformylbenzene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.009.805 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 210-784-8
PubChem CID
UNII
  • InChI=1S/C8H6O2/c9-5-7-1-2-8(6-10)4-3-7/h1-6H
    Key: KUCOHFSKRZZVRO-UHFFFAOYSA-N
  • C1=CC(=CC=C1C=O)C=O
Properties
C8H6O2
Molar mass 134.132
Appearancewhite to beige
Density 1.06 g/mL
Melting point 114–117 °C (237–243 °F; 387–390 K)
Boiling point 245-248
Hazards
GHS labelling: [1]
GHS-pictogram-skull.svg GHS-pictogram-exclam.svg
Danger
H302, H311, H315, H319, H335
P261, P280, P304+P340, P305+P351+P338, P405, P501
Flash point 76 °C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Terephthalaldehyde (TA) is an organic compound with the formula C6H4(CHO)2. It is one of three isomers of benzene dicarboxaldehyde, in which the aldehyde moieties are positioned in the para conformation on the benzene ring. Terephthalaldehyde appears as a white to beige solid, typically in the form of a powder. It is soluble in many organic solvents, such as alcohols (e.g., methanol or ethanol) and ethers (e.g., tetrahydrofuran or diethylether).

Contents

Preparation

Terepthalaldehyde can be synthesised from p-xylene in two steps. [2] First, p-xylene can be reacted with bromine to create α,α,α',α'-Tetrabromo-p-xylene. Next, sulphuric acid is introduced to create terephthaldehyde. Alternative procedures also describe the conversion of similar p-xylene derivatives into terephthalaldehyde.

Reactions and applications

Terphthalaldehyde is used in the preparation of imines, which are also commonly referred to as Schiff bases, following a condensation reaction with amines. During this reaction, water is also formed. This reaction is by definition reversible, thus creating an equilibrium between aldehyde and amine on one side, and the imine and water on the other. However, due to aromatic conjugation between the imine group and benzene ring, the imines are relatively stable and will not easily hydrolyse back to the aldehyde. [3] When in an acidic aqueous environment, however, imines will start to hydrolyse more easily. [4] Typically, an equilibrium between the imine and aldehyde is formed, which is dependent on the concentration of the relevant compounds and the pH of the solution.

Imines from terephthalaldehyde find use in the preparation of metal-organic coordination complexes. In addition, terepthaldehyde is a commonly used monomer in the production of imine polymers, also called polyimines. [5] It finds further use in the synthesis of covalent organic frameworks (COFs), [6] and It is used as a precursor for the preparation of paramagnetic microporous polymeric organic frameworks (POFs) through copolymerization with pyrrole, indole, and carbazole. Due to the characteristic metal-coordinating properties of imines, terephthalaldehyde finds common use in synthesis of molecular cages. [7]

Terephthalaldehyde is also a commonly used intermediate or starting material in the preparation of a broad variety of organic compounds, such as pharmaceuticals, dyes and fluorescent whitening agents.

Related Research Articles

<span class="mw-page-title-main">Carboxylic acid</span> Organic compound containing a –C(=O)OH group

In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO2H, sometimes as R−C(O)OH with R referring to an organyl group, or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

The following outline is provided as an overview of and topical guide to organic chemistry:

<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

In organic chemistry, an imine 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 bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.

Reductive amination is a form of amination that involves the conversion of a carbonyl group to an amine via an intermediate imine. The carbonyl group is most commonly a ketone or an aldehyde. It is a common method to make amines and is widely used in green chemistry since it can be done catalytically in one-pot under mild conditions. In biochemistry, dehydrogenase enzymes use reductive amination to produce the amino acid, glutamate. Additionally, there is ongoing research on alternative synthesis mechanisms with various metal catalysts which allow the reaction to be less energy taxing, and require milder reaction conditions. Investigation into biocatalysts, such as imine reductases, have allowed for higher selectivity in the reduction of chiral amines which is an important factor in pharmaceutical synthesis.

<span class="mw-page-title-main">Molecular Borromean rings</span> Molecule composed of three interlocked rings

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<span class="mw-page-title-main">Palladium(II) acetate</span> Chemical compound

Palladium(II) acetate is a chemical compound of palladium described by the formula [Pd(O2CCH3)2]n, abbreviated [Pd(OAc)2]n. It is more reactive than the analogous platinum compound. Depending on the value of n, the compound is soluble in many organic solvents and is commonly used as a catalyst for organic reactions.

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<span class="mw-page-title-main">Carbonyl condensation</span> Organic reaction of carbonyl compounds with amines to imines

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<span class="mw-page-title-main">Phthalaldehyde</span> Chemical compound

Phthalaldehyde (sometimes also o-phthalaldehyde or ortho-phthalaldehyde, OPA) is the chemical compound with the formula C6H4(CHO)2. It is one of three isomers of benzene dicarbaldehyde, related to phthalic acid. This pale yellow solid is a building block in the synthesis of heterocyclic compounds and a reagent in the analysis of amino acids. OPA dissolves in water solution at pH < 11.5. Its solutions degrade upon UV illumination and exposure to air.

<span class="mw-page-title-main">Tris(2-aminoethyl)amine</span> Chemical compound

Tris(2-aminoethyl)amine is the organic compound with the formula N(CH2CH2NH2)3. This colourless liquid is soluble in water and is highly basic, consisting of a tertiary amine center and three pendant primary amine groups. Tris(2-aminoethyl)amine is commonly abbreviated as tren or TREN. It is used a crosslinking agent in the synthesis of polyimine networks and a tripodal ligand in coordination chemistry.

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4,4′-Methylenedianiline (MDA) is an organic compound with the formula CH2(C6H4NH2)2. It is a colorless solid, although commercial samples can appear yellow or brown. It is produced on an industrial scale, mainly as a precursor to polyurethanes.

<i>N</i>-Sulfinyl imine

N-Sulfinyl imines are a class of imines bearing a sulfinyl group attached to nitrogen. These imines display useful stereoselectivity reactivity and due to the presence of the chiral electron withdrawing N-sulfinyl group. They allow 1,2-addition of organometallic reagents to imines. The N-sulfinyl group exerts powerful and predictable stereodirecting effects resulting in high levels of asymmetric induction. Racemization of the newly created carbon-nitrogen stereo center is prevented because anions are stabilized at nitrogen. The sulfinyl chiral auxiliary is readily removed by simple acid hydrolysis. The addition of organometallic reagents to N-sulfinyl imines is the most reliable and versatile method for the asymmetric synthesis of amine derivatives. These building blocks have been employed in the asymmetric synthesis of numerous biologically active compounds.

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<span class="mw-page-title-main">Isophthalaldehyde</span> Chemical compound

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References

  1. "Terephthalaldehyde". pubchem.ncbi.nlm.nih.gov.
  2. Snell, J. M.; Weissberger, A. (1940). "Terepthalaldehyde". Organic Syntheses. 20: 92. doi:10.15227/orgsyn.020.0092.
  3. Schoustra, S. K.; Dijksman, J. A.; Zuilhof, H.; Smulders, M. M. J. (2021). "Molecular control over vitrimer-like mechanics – tuneable dynamic motifs based on the Hammett equation in polyimine materials". Chemical Science. 12 (1): 293–302. doi:10.1039/d0sc05458e. ISSN   2041-6520. PMC   8178953 . PMID   34163597.
  4. Schoustra, S.K.; Asadi, V.; Smulders, M.M.J. (2024). "Probing the Solubility of Imine-Based Covalent Adaptable Networks". ACS Appl. Polym. Mater. 4 (1): 79–89. doi:10.1021/acsapm.3c01472. PMC   10788871 . PMID   38230365.
  5. Taynton, Philip; Zhu, Chengpu; Loob, Samuel; Schoemaker, Richard; Pritchard, James; Jin, Yinghua; Zhang, Wei (2016). "Re-healable polyimine thermosets: polymer composition and moisture sensitivity". Polymer Chemistry. 7 (46): 7052–7056. doi:10.1039/c6py01395c.
  6. Qu, Fei; Yan, Hang; Li, Kexin; You, JinMao; Han, Wenli (2020). "A covalent organic framework–MnO2 nanosheet system for determination of glutathione". Journal of Materials Science. 55 (23): 10022–10034. Bibcode:2020JMatS..5510022Q. doi:10.1007/s10853-020-04754-9. S2CID   218592879.
  7. Belowich, Matthew E.; Stoddart, J. Fraser (2012). "Dynamic imine chemistry". Chem. Soc. Rev. 41 (6): 2003–2024. doi:10.1039/C2CS15305J. PMID   22310886.