1,4-Benzoquinone
From Wikipedia, the free encyclopedia
| 1,4-Benzoquinone | |
|---|---|
 |
 |
| IUPAC name |
Cyclohexa-2,5-diene-1,4-dione
|
| Other names | p-benzoquinone; p-quinone |
| Identifiers | |
| CAS number | 106-51-4 |
| RTECS number | DK2625000 |
| SMILES |
C1=CC(=O)C=CC1=O
|
| Properties | |
| Molecular formula | C6H4O2 |
| Molar mass | 108.095 g/mol |
| Appearance | Yellow solid |
| Density | 1.318 g/cm3 at 20 °C, solid |
| Melting point |
115 °C |
| Boiling point |
Sublimes |
| Solubility in water | Slightly soluble |
| Solubility | Slightly soluble in petroleum ether; soluble in acetone; very soluble in ethanol, benzene, diethyl ether |
| Hazards | |
| R-phrases | R23/25 R36/37/38 R50 |
| S-phrases | S26 S28 S45 S61 |
| Related compounds | |
| Related compounds | 1,2-Benzoquinone |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
| Infobox references | |
1,4-Benzoquinone is the chemical compound with the formula C6H4O2. In pure state, it forms bright yellow crystals with characteristic irritating odor, resembling that of chlorine; impure samples are often dark colored due to the presence of quinhydrone (1:1 complex of quinone with hydroquinone). This nonaromatic six-membered ring compound is the oxidized derivative of 1,4-hydroquinone.[1] The molecule is multifunctional: it exhibits properties of a ketone, forming an oxime; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions, especially those typical for α,β-unsaturated ketones. 1,4-Benzoquinone is sensitive towards both strong mineral acids and alkali, which cause condensation and decomposition of the compound.
Contents |
[edit] Applications in organic synthesis
It is used as a hydrogen acceptor and oxidant in organic synthesis.[2] 1,4-Benzoquinone serves as a dehydrogenation reagent. It is also used as a dienophile in Diels Alder reactions.[3]
Benzoquinone reacts with acetic anhydride and sulfuric acid to the triacetate of 1,3,4-trihydroxybenzene. This reaction is called the Thiele reaction [4] after Johannes Thiele who first described the reaction in 1898. An application is found in total synthesis [5]:
Benzoquinone is also used to suppress double bond migration during Olefin Metathesis reactions.
[edit] Related 1,4-benzoquinones
A variety of derivatives and analogues are known. Illustrative examples:
- 1,4-Naphthoquinone, derived by oxidation of naphthalene with chromium trioxide.[6]
- 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), a stronger oxidant and dehydrogenation agent than 1,4-benzoquinone.[7]
- Ubiquinone-1, a naturally occurring 1,4-benzoquinone.
- Chloro-p-benzoquinone, (CAS no. [695-99-8])[8]
- Chloranil, 1,4-C6Cl4O2, a stronger oxidant and dehydrogenation agent than 1,4-benzoquinone.
[edit] See also
[edit] References
- ^ H. W. Underwood, Jr. and W. L. Walsh (1943), "Quinone", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0553; Coll. Vol. 2: 553
- ^ Yang, T.-K.; Shen, C.-Y. ”1,4-Benzoquinone” in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289.
- ^ Oda, M.; Kawase, T.; Okada, T.; Enomoto, T. (1998), "2-Cyclohexene-1,4-dione", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv9p0186; Coll. Vol. 9: 186
- ^ Ueber die Einwirkung von Essigsäure-anhydrid auf Chinon und auf Dibenzoylstyrol (pp. 1247–1249) Johannes Thiele Berichte der deutschen chemischen Gesellschaft Volume 31, Issue 1, pages 1247–1249 1898 doi:10.1002/cber.189803101226
- ^ Stereoselective Total Synthesis and Enantioselective Formal Synthesis of the Antineoplastic Sesquiterpene Quinone Metachromin A Wanda P. Almeida, and Carlos Roque D. Correia J. Braz. Chem. Soc., Vol. 10, No. 5, 401–414, 1999 doi:10.1590/S0103-50531999000500011.
- ^ E. A. Braude E. A.; Fawcett, J. S. (1963), "1,4-Naphthoquinone", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0698; Coll. Vol. 4: 698
- ^ Vogel, E.; Klug, W.; Breuer, A. (1988), "1,6-Methano[10]annulene", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0731; Coll. Vol. 6: 731
- ^ Harman, R. E. (1963), "Chloro-p-benzoquinone", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0148; Coll. Vol. 4: 148
