Carbazole

Carbazole
IUPAC name

9H-carbazole
Other names

9-azafluorene, dibenzopyrrole, diphenylenimine, diphenyleneimide, USAF EK-600
Identifiers
CAS number 86-74-8 Y
PubChem 6854
ChemSpider 6593 Y
UNII 0P2197HHHN Y
DrugBank DB07301
KEGG C08060 Y
ChEBI CHEBI:27543 Y
ChEMBL CHEMBL243580 Y
Jmol-3D images Image 1
Properties
Molecular formula C12H9N
Molar mass 167.206 g mol−1[1]
Density 1.301g/cm^3
Melting point

246.3 °C[1]
Boiling point

354.69 °C[1]
Hazards
Flash point 220 °C[1]
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Carbazole is an aromatic heterocyclic organic compound. It has a tricyclic structure, consisting of two six-membered benzene ring fused on either side of a five-membered nitrogen-containing ring. The compound's structure is based on the indole structure but in which a second benzene ring is fused onto the five-membered ring at the 2–3 position of indole (equivalent to the 4a–9a double bond in carbazole).

Contents

Synthesis

A classic laboratory organic synthesis for carbazole is the Borsche–Drechsel cyclization.[2][3]

In the first step phenylhydrazine is condensed with cyclohexanone to the corresponding imine. The second step is a hydrochloric acid catalyzed rearrangement reaction and ring-closing reaction to tetrahydrocarbazole. In one modification both steps are rolled into one by carrying out the reaction in acetic acid.[4] In the third step this compound is oxidized by Red lead to carbazole itself. Another classic is the Bucherer carbazole synthesis

A second method for the synthesis of carbazole is the Graebe–Ullmann reaction. In the first step, an N-phenyl-1,2-diaminobenzene (N-phenyl-o-phenylenediamine) is converted into a diazonium salt which instantaneously forms a 1,2,3-triazole. The triazole is unstable and at elevated temperatures nitrogen is set free and the carbazole is formed.[5][6][7]

Supply and demand

2010 and 2011 have seen wide spread shortages of Carbazole.

Use

Carbozole is used in the production of Pigment Violet 23.

Related aromatic compounds

References

  1. ^ a b c d Lide, David R. (2007). CRC Handbook of Chemistry and Physics, 88th Edition. CRC Press. pp. 3–86. ISBN 978-0849304880. 
  2. ^ W. Borsche (1908). "Ueber Tetra- und Hexahydrocarbazolverbindungen und eine neue Carbazolsynthese. (Mitbearbeitet von. A. Witte und W. Bothe.)". Justus Liebig's Annalen der Chemie 359 (1–2): 49–80. doi:10.1002/jlac.19083590103. 
  3. ^ E. Drechsel (1888). "Ueber Elektrolyse des Phenols mit Wechselströmen". Journal für praktische Chemie 38 (1): 65–74. doi:10.1002/prac.18880380105. 
  4. ^ Organic Syntheses, Coll. Vol. 4, p.884 (1963); Vol. 30, p.90 (1950). Link
  5. ^ Graebe-Ullmann reaction
  6. ^ Carl Graebe and Fritz Ullmann (1896). "Ueber eine neue Carbazolsynthese". Justus Liebig's Annalen der Chemie 291 (1): 16–17. doi:10.1002/jlac.18962910104. 
  7. ^ O. Bremer (1934). "Über die Bedeutung der Graebe-Ullmannschen Carbazolsynthese und deren Übertragung auf N-substituierte Pyridino-triazole". Justus Liebigs Annalen der Chemie 514: 279–291. doi:10.1002/jlac.19345140116. 

External links