2-Ethylanthraquinone

2-Ethylanthraquinone

Names
Other names 2-Ethyl-9,10-anthracenedione
Identifiers
CAS Number	84-51-5
ChEMBL	ChEMBL42355
ChemSpider	6514
EC Number	201-535-4
Jmol interactive 3D	Image
InChI InChI=1S/C16H12O2/c1-2-10-7-8-13-14(9-10)16(18)12-6-4-3-5-11(12)15(13)17/h3-9H,2H2,1H3 Key: SJEBAWHUJDUKQK-UHFFFAOYSA-N InChI=1/C16H12O2/c1-2-10-7-8-13-14(9-10)16(18)12-6-4-3-5-11(12)15(13)17/h3-9H,2H2,1H3 Key: SJEBAWHUJDUKQK-UHFFFAOYAW
SMILES O=C2c1c(cccc1)C(=O)c3c2ccc(c3)CC
Properties
Chemical formula	C16H12O2
Molar mass	236.27 g/mol
Appearance	white to yellowish crystals or powder
Density	1.231g/cm3
Melting point	105 °C (221 °F; 378 K)
Boiling point	415.4 @ 760mmHg
Hazards
S-phrases	S24 S25
Flash point	155.4 °C (311.7 °F; 428.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
verify (what is  ?)
Infobox references

2-Ethylanthraquinone is an organic compound that is a derivative of anthraquinone. It is pale yellow solid is used in the industrial production of hydrogen peroxide (H₂O₂).^[1][2]

Production

2-Ethylanthraquinone is prepared from the reaction of phthalic anhydride and ethylbenzene:

C₆H₄(CO)₂O + C₆H₅Et → C₆H₄(CO)₂C₆H₃Et + H₂O.

Both phthalic anhydride and ethylbenzene are readily available, being otherwise used in the large-scale production of plastics.

Uses

Hydrogen peroxide is produced industrially by the anthraquinone process which involves using 2-alkyl-9,10-anthraquinones for hydrogenation. Many derivatives of anthraquinone are used but 2-ethylanthraquinone is common because of its high selectivity. The hydrogenation of the unsubsituted ring can reach 90% selectivity by using 2-ethylanthraquinone. Hydrogenation follows the Riedl-Pfleiderer, or autoxidation, process:

The hydrogenation of 2-ethylanthraquinone is catalyzed by palladium. Hydrogenation produces both 2-ethylanthrahydroquinone and tetrahydroanthraquinone. The tetrahydro derivative of 2-alkylanthraquinone is easily hyrdrogenated but is more difficult to oxidize. The formation of the tetrahyrdo derivative can be suppressed through the selection of catalysts, solvents, and reaction conditions. Some suggested solvent mixtures are polyalkylated benzenes and alkyl phosphates or tetraalkyl ureas, trimethylbenzenes and alkylcyclohexanol esters, and methylnaphthalene and nonyl alcohols.

References

1. Goor, G.; Glenneberg, J.; Jacobi, S. (2007). "Hydrogen Peroxide". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_443.pub2.
2. Römpp CD 2006, Georg Thieme Verlag 2006