2,3-dichloro-5,6-dicyano-1,4-benzoquinone

Structural formula
General
Surname	2,3-dichloro-5,6-dicyano-1,4-benzoquinone
other names	DDQ
Molecular formula	C 8 Cl 2 N 2 O 2
Brief description	yellow to orange powder
External identifiers / databases
EC number	201-542-2
ECHA InfoCard	100.001.402
PubChem	6775
Wikidata	Q209177
properties
Molar mass	227.00 g mol −1
Physical state	firmly
Melting point	210-217 ° C
solubility	soluble in benzene, dioxane, acetic acid and ethanol; somewhat soluble in chloroform and dichloromethane;
safety instructions
H and P phrases	H: 332-318-312-301
	EUH: 029
	P: 301 + 310-305 + 351 + 338-302 + 352-310-280-402 + 404-304 + 340
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (or DDQ from English 2,3-dichloro-5,6-dicyano-1,4-benzoquinone) is an organic compound and is used as an oxidative reagent in of organic chemistry its application. DDQ is used for the oxidative dehydrogenation of alcohols , phenols and steroid ketones . DDQ is also used in protecting group technology in the cleavage of p- methoxy and 3,4-dimethoxybenzyl ethers. DDQ decomposes in water, but is stable in the presence of aqueous mineral acids.

synthesis

In 1906 Johannes Thiele and Fritz Günther published a reaction sequence consisting of cyanation and chlorination of 1,4-benzoquinone . A one-step reaction for the synthesis of DDQ was reported in 1965 by Derek Walker and Thomas D. Waugh starting from 2,3-dicyanohydroquinone .

stability

DDQ is hydrolyzed by water, splitting off the very toxic hydrocyanic acid (HCN). Low temperatures and a weakly acidic environment increase the stability.

use

DDQ is a reagent that is used for oxidation and as a radical acceptor.

Reactions

Dehydrogenation

DDQ can be used for the dehydrogenation of α, β-unsaturated carbonyl compounds, as shown in the example of a steroid.

Flavoring

In the presence of acids, aromatic steroids are accessible by dehydration.

Oxidative coupling reactions

DDQ can also be used for oxidative couplings.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f data sheet 2,3-dichloro-5,6-dicyano-1,4-benzoquinone from Acros, accessed on January 1, 2012.
↑ ^a ^b Braude. EA, Linstead, RP, and Wooldridge, KRH: Hydrogen Transfer. 9. The selective dehydrogenation of unsaturated alcohols by high-potential quinones . In: Journal of the American Chemical Society . August 1956, pp. 3070-3074. doi : 10.1039 / JR9560003070 .
↑ Becker. HD ,: Quinone Dehydrogenation .I. Oxidation Of Monohydric Phenols . In: Journal of Organic Chemistry . 30, No. 4, 1965, pp. 982-989. doi : 10.1021 / jo01015a006 .
^ AB Turner, HJ Ringold: Applications of high-potential quinones. Part I. The mechanism of dehydrogenation of steroidal ketones by 2,3-dichloro-5,6-dicyanobenzoquinone . In: Journal of the Chemical Society . 1967, pp. 1720-1730. doi : 10.1039 / J39670001720 .
↑ Yuji Oikawa, Tadao Yoshioka, Osamu Yonemitsu: "Specific removal of o-methoxybenzyl protection by DDQ oxidation", in: Tetrahedron Lett. , 1982 , 23 , pp. 885-888; doi : 10.1016 / S0040-4039 (00) 86974-9 .
↑ Johannes Thiele, Fritz Günther: About derivatives of Dicyanhydrochinons , in: Justus Liebigs Annalen der Chemie , 1906, Volume 349, Issue 1, pp. 45-66; doi : 10.1002 / jlac.19063490103 .
↑ Brown.W, Turner. AB, AB Turner: Application of High-potential Quinones. 7. Synthesis of steroidal phenanthrenes by double methyl migration . In: J. Chem. Soc. C. . No. 14, 1971, pp. 2566-2572. doi : 10.1039 / J39710002566 .
↑ YH.Zhang, CJ. Li, and Wooldridge, KRH: DDQ-Mediated Direct Cross-Dehydrogenative-Coupling (CDC) between Benzyl Ethers and Simple Ketones . In: Journal of the American Chemical Society . 128, No. 13, 2006, pp. 4242-4243. doi : 10.1021 / ja060050p .

Web links

"Like Neurons in the Brain": A Molecular Computer that Evolves ( Memento from December 12, 2010 in the Internet Archive )

[acros-1] ↑ ^a ^b ^c ^d ^e ^f data sheet 2,3-dichloro-5,6-dicyano-1,4-benzoquinone from Acros, accessed on January 1, 2012.

[Braude_1956-2] Braude. EA, Linstead, RP, and Wooldridge, KRH: Hydrogen Transfer. 9. The selective dehydrogenation of unsaturated alcohols by high-potential quinones . In: Journal of the American Chemical Society . August 1956, pp. 3070-3074. doi : 10.1039 / JR9560003070 .

[3] Becker. HD ,: Quinone Dehydrogenation .I. Oxidation Of Monohydric Phenols . In: Journal of Organic Chemistry . 30, No. 4, 1965, pp. 982-989. doi : 10.1021 / jo01015a006 .

[4] AB Turner, HJ Ringold: Applications of high-potential quinones. Part I. The mechanism of dehydrogenation of steroidal ketones by 2,3-dichloro-5,6-dicyanobenzoquinone . In: Journal of the Chemical Society . 1967, pp. 1720-1730. doi : 10.1039 / J39670001720 .

[5] Yuji Oikawa, Tadao Yoshioka, Osamu Yonemitsu: "Specific removal of o-methoxybenzyl protection by DDQ oxidation", in: Tetrahedron Lett. , 1982 , 23 , pp. 885-888; doi : 10.1016 / S0040-4039 (00) 86974-9 .

[6] Johannes Thiele, Fritz Günther: About derivatives of Dicyanhydrochinons , in: Justus Liebigs Annalen der Chemie , 1906, Volume 349, Issue 1, pp. 45-66; doi : 10.1002 / jlac.19063490103 .

[7] Brown.W, Turner. AB, AB Turner: Application of High-potential Quinones. 7. Synthesis of steroidal phenanthrenes by double methyl migration . In: J. Chem. Soc. C. . No. 14, 1971, pp. 2566-2572. doi : 10.1039 / J39710002566 .

[8] YH.Zhang, CJ. Li, and Wooldridge, KRH: DDQ-Mediated Direct Cross-Dehydrogenative-Coupling (CDC) between Benzyl Ethers and Simple Ketones . In: Journal of the American Chemical Society . 128, No. 13, 2006, pp. 4242-4243. doi : 10.1021 / ja060050p .