Phthalaldehyde
From Wikipedia, the free encyclopedia
| Phthalaldehyde | |
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| IUPAC name | o-Phthalaldehyde |
| Other names | o-Phthalic dicarboxaldehyde Benzene-1,2-dicarboxaldehyde Phthaldialdehyde |
| Identifiers | |
| CAS number | [] |
| RTECS number | TH6950000 |
| Properties | |
| Molecular formula | C8H6O2 |
| Molar mass | 134.13 g/mol |
| Appearance | yellow solid |
| Melting point |
55.5–56 °C |
| Solubility | organic solvents |
| Hazards | |
| R-phrases | 36/37/38 |
| S-phrases | 26-28-36 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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o-Phthalaldehyde is the chemical compound with the formula C6H4(CHO)2. Often abbreviated OPA, the molecule is a dialdehyde, consisting of two formyl (CHO) groups attached to adjacent carbon centres on a benzene ring. This pale yellow solid is a building block in the synthesis of heterocyclic compounds and a reagent in the analysis of amino acids.
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[edit] Synthesis
The molecule was first described in 1887 when it was prepared from α,α,α',α’-tetrachloro-ortho-xylene.[1] A more modern synthesis is similar: the hydrolysis of the related tetrabromoxylene using potassium oxalate, followed by purification by steam distillation.[2] The reactivity of OPA is complicated by the fact that with water it forms both a mono- and dihydrate, C6H4(CHO)(CH2OH) and C6H4(CH2OH)2, respectively.[3]
[edit] Isomeric phthalaldehydes
Related to o-phthalaldehyde are the meta and para isomers, which are respectively named isophthalaldehyde (m.p. 87-88 °C, CAS# 626-19-7) terephthalaldehyde (m.p. 114-116 °C, CAS# 623-27-8).
[edit] References
- ^ Colson, A.; Gautier, H. "Nouveau Mode de Chloruration des Carbures" Annales de Chimie (Paris), 1887, volume 6, number 11, pp. 28.
- ^ Bill J. C.; Tarbell, D. S. “o-Phthalaldehyde” Organic Syntheses, Collected Volume 4, p.807 (1963). http://www.orgsyn.org/orgsyn/pdfs/CV4P0807.pdf
- ^ Zuman, H. "Reactions of Orthophthalaldehyde with Nucleophiles" Chemical Reviews 2004; volume 104, pp. 3217-3238. DOI:10.1021/cr0304424
