2,5-dibromohydroquinone

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Structural formula
Structural formula of 2,5-dibromohydroquinone
General
Surname 2,5-dibromohydroquinone
other names
  • 2,5-dibromobenzene-1,4-diol
  • 2,5-dihydroxy-1,4-dibromobenzene
Molecular formula C 6 H 4 Br 2 O 2
Brief description

white to beige crystals

External identifiers / databases
CAS number 14753-51-6
EC number 629-317-8
ECHA InfoCard 100.157.509
PubChem 280945
ChemSpider 247423
Wikidata Q209230
properties
Molar mass 267.90 g mol −1
Physical state

firmly

Melting point
  • 191-194 ° C
  • 186 ° C
safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 315-319-335
P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

2,5-Dibromohydroquinone is a chemical compound that belongs to the group of phenols . Together with 2,3-dibromohydroquinone and 2,6-dibromohydroquinone, it is one of the three positionally isomeric dibromohydroquinones.

Historical

2,5-Dibromohydroquinone was first examined by Rudolf Benedikt in 1880.

presentation

2,5-Dibromohydroquinone can be produced from hydroquinone by bromination with elemental bromine in acetic acid .

Production of 2,5-dibromohydroquinone

The synthesis from 1,4-benzoquinone with hydrobromic acid is also possible.

Production of 2,5-dibromohydroquinone from benzoquinone

Reactions

2,5-Dibromohydroquinone can easily be oxidized (e.g. with iron (III) chloride ) to yellow 2,5-Dibromobenzoquinone (CAS number: 1633-14-3, melting point 188–190 ° C).

Oxidation of 2,5-dibromohydroquinone to 2,5-dibromobenzoquinone

The nitration of 2,5-dibromohydroquinone with nitric acid fails, oxidation occurs and 2,5-dibromoquinone is formed.

Reaction of 2,5-dibromohydroquinone with nitric acid

Complete methylation with dimethyl sulfate leads to 1,4-dibromo-2,5-dimethoxybenzene , which melts at 144–147 ° C.

Methylation of 2,5-dibromohydroquinone

The dipropyl ether can be prepared by Williamson ether synthesis with 1-bromopropane in ethanol . Its melting point is 79–81 ° C. In a similar way, the dihexyl ether can be synthesized with 1-bromohexane in DMF and the dioctadecyl ether with 1-bromooctadecane (melting point 90-92 ° C.)

Individual evidence

  1. ↑ a b c d data sheet 2,5-dibromohydroquinone from Sigma-Aldrich , accessed on March 17, 2011 ( PDF ).
  2. ^ Association of authors: Organikum , 19th edition, Johann Ambrosius Barth, Leipzig · Berlin · Heidelberg 1993, ISBN 3-335-00343-8 , p. 653.
  3. ↑ R. Benedikt: About dibromohydroquinone in monthly books for chemistry . 1880, 1 (1), pp. 345-348. doi : 10.1007 / BF01517076
  4. ↑ a b RWTH Aachen working regulations
  5. ↑ Benzenequinone and its derivatives , quarterly journal of the Natural Research Society in Zurich. Full text
  6. ↑ M. Kohn, LW Guttmann: On the knowledge of the bromine substitution products of hydroquinone. VII. Communication on bromophenols in monthly journals for chemistry 1924 , 45 (10), pp. 573-588. doi : 10.1007 / BF01524599
  7. ↑ External identifiers or database links for 1,4-dibromo-2,5-dimethoxybenzene : CAS number: 2674-34-2, EC number: 629-351-3, ECHA InfoCard: 100.157.540 , Wikidata : Q72464184 .
  8. ↑ Data 2.5 dibromohydroquinone from Acros, accessed on 20 February 2010 .
  9. ↑ a b Dissertation: Solid-state olefin methathesis , GWOakley, University of Florida, 2004.
  10. ↑ O. Bolton, K. Lee, H.-J. Kim, KY Lin, J. Kim: Activating efficient phosphorescence from purely organic materials by crystal design in Nature Chemistry 2011, 3 , pp. 205-210. doi : 10.1038 / nchem.984