|Carbazole Basic information|
|Introduction Extraction Production|
|Synonyms:||Diphenylenedimine;Diphenyleneimide;Diphenyleneimine;Diphenylenimide;Skf 20091;USAF ek-600;9-Dibenzo-[b,d]-pyrrole;9-Azofluoerene|
|Product Categories:||Organics;Carbazoles;Intermediates of Dyes and Pigments;Carbazoles (for Conduting Polymer Research);Functional Materials;Reagents for Conducting Polymer Research;Alpha Sort;C;CA - CGEnvironmental Standards;CAlphabetic;PAHs;Volatiles/ Semivolatiles;CA - CG;Pesticides&Metabolites;Stains and Dyes;Stains&Dyes, A to;CA - CGAntibiotics;Alphabetic;Chemical Structure;Others;OLED materials,pharm chemical,electronic|
|Carbazole Chemical Properties|
|Melting point||243-246 °C(lit.)|
|Boiling point||355 °C(lit.)|
|vapor pressure||400 mm Hg ( 323 °C)|
|refractive index||1.6192 (estimate)|
|form||Crystalline Powder, Flakes, or Chunks|
|color||Beige-yellow or beige-brownish|
|Water Solubility||<0.1 g/100 mL at 19 ºC|
|Stability:||Stable. Combustible. Incompatible with strong oxidizing agents, nitrogen oxides, potassium hydroxide.|
|CAS DataBase Reference||86-74-8(CAS DataBase Reference)|
|IARC||2B (Vol. 32, Sup 7, 71, 103) 2013|
|NIST Chemistry Reference||Carbazole(86-74-8)|
|EPA Substance Registry System||Carbazole (86-74-8)|
|RIDADR||UN 2811 6.1/PG 3|
A) At present, the domestic production of carbazole method is based on crude anthracene as raw material, generally do not co-produce refined anthracene, poor economic benefits. The method is sulfuric acid extraction, forming carbazole sulfate salt solution, and then using ammonia water recoil to precipitate carbazole. Jiangsu dafeng chemical plant used this method, has now stopped production, the reason is :(1) low product purity. Containing a large amount of impurities such as acridine, the purity is less than 90%. (2) can not produce refined anthracene, no competitiveness. (3) Equipment material requirements are high, serious corrosion. (4) The discharge of waste water is large and the pollution is serious. KOH melting method was used to produce carbazole in foreign countries, but it has never been put into industrial production. The method of synthesizing carbazole has also been tested abroad. The method is closed-loop dehydrogenation of o-aminobenzene with ammonia or chlorobenzene as raw material. The advantage of this method is that raw materials are easy to obtain, but the disadvantage is that there is no market competitiveness, because :(1) the synthetic route is long and the reaction steps are many. Each step of the reaction requires complex pre - and post-processing, and the separation equipment and operation costs are particularly high. (2) Low conversion rate. Most reactions are accompanied by side reactions, and the final conversion rate is low due to the long route. (3) Large amount of waste treatment, high cost of environmental protection. From the current market share, the main source of carbazole or coal tar (anthracene oil). The major carbazole manufacturers in the world, such as RUTGERS in Germany, DEIA in The Czech Republic and JORYU in Japan, are all the same, and all of them are combined production of anthracene and carbazole. Carbazole is industrially derived from coal tar. The raw material for extraction is the fraction of I anthracene oil in continuous distillation of tar. The initial distillation point is 300℃, and the distillation amount is 95% before 350℃. The yield of I anthracene oil accounts for 12-14% of tar. After cooling crystallization of I anthracene oil, vacuum filtration or casting to remove part of the oil, containing anthracene 25-30%, carbazole 20-25%, about 30% phenanthrene. Phenanthrene is easily dissolved in oil, which is used to separate phenanthrene from anthracene and carbazole. There are two methods to separate anthracene and carbazole: 1. The distillation separation method utilizes the boiling point difference with carbazole (boiling point of anthracene is 340.7℃, carbazole is 355℃), uses the emulsifying column with tower effect equivalent to 40 theoretical trays for distillation, and the reflux ratio is 19: 1. Industrial anthracene containing 85% anthracene on average can be obtained by cutting the fraction at the top temperature of 310-344℃, and then industrial carbazole containing 85% carbazole can be obtained by cutting the fraction at 348-355℃. 2. Potassium melting method using carbazole potassium melt insoluble in oil and precipitation characteristics, the crude anthracene after heating and melting, add flake potash, separated by carbazole potassium compound, hydrolysis in the hydrolysis tank, the crude carbazole and alkali liquid generated by centrifuge separation, water washing and steam blowing washing, the crude carbazole. After drying, refined carbazole was sublimated at 180-240℃ and recrystallized with xylene, the purity of commercial carbazole was 95-98%. In addition, carbazole can also be synthesized from o-aminobenzene.
Carbazole can be extracted from coal tar and then separated by distillation; It can also be synthesized from o-aminobenzene and refined by recrystallization with xylene.
(1) Synthesis method with o-aminobenzidine as raw material, through nitrite treatment, the preparation of 1-phenyl-1, 2, 3-benzotriazole, after heating, lose nitrogen and generate carbazole.
(2) Sulfuric acid method to dissolve crude anthracene with chlorobenzene or other solvents, phenanthrene, fluorene and other substances in crude anthracene because of insolubility and separate anthracene and carbazole, the reaction of anthracene and carbazole in sulfuric acid, carbazole and sulfuric acid to form carbazole sulfate and separate anthracene, carbazole sulfate hydrolysis, after filtration, drying to obtain the finished product.
(3) Solvent-distillation method of crude anthracene with coking byproduct heavy benzene (160~200℃) fraction dissolution, in the crude anthracene phenanthrene, fluorene and other substances and anthracene, carbazole separated, anthracene and carbazole in the distillation tower for high temperature distillation, after a distillation, can be obtained containing carbazole 85%~90% of the product, the yield of 65%.