Carbazole

Chemical properties

white crystals or light brown powder

Chemical properties

In the laboratory method, the ring-closure dehydrogenation of o-aminobiphenyl is made from ammonia or chlorobenzene. In the industrial production method, 90% of the world's carbazole is obtained from coal tar; it can also be synthesized from o-aminobiphenyl, and then purified by recrystallization from xylene. (1) Synthesis method: 1-phenyl-1,2,3-benzotriazole is prepared by using o-aminodiphenylamine as raw material and treated with nitrous acid. After heating, nitrogen is lost to form carbazole. (2) Sulfuric acid method: Dissolve the crude anthracene with chlorobenzene or other solvents. The phenanthrene, fluorene and other substances in the crude anthracene are separated from anthracene and carbazole due to insolubility. Anthracene and carbazole are added to sulfuric acid for reaction. Then it forms carbazole sulfate with sulfuric acid and separates from anthracene. After hydrolyzing carbazole sulfate, the finished product is obtained by filtration and drying. (3) Solvent-rectification method: The crude anthracene is dissolved in the heavy benzene (160~200℃) by-product of coking, and the phenanthrene, fluorene and other substances in the crude anthracene are separated from anthracene and carbazole. High-temperature rectification is carried out in the distillation tower, and after one rectification, a product containing 85% to 90% of carbazole can be obtained, and the yield is 65%.

The Uses of Carbazole

Carbazole and its derivatives are widely used as an intermediate in synthesis of pharmaceuticals, agrochemicals, dyes, pigments and other organic compounds.?carbazole is also used in luminescence chemistry as a photosensitizing and additional charge transport material. Carbazole structure is a motif in pharmaceuticals such as carvedilol used to treat high blood pressure and to prevent cardiac arrhythmias and angina.

The Uses of Carbazole

Important dye intermediate. Used in making photographic plates sensitive to ultraviolet light. Reagent for lignin, carbohydrates, and formaldehyde.

The Uses of Carbazole

Intermediate in production of dyes and UVsensitive photographic plates.

What are the applications of Application

Carbazole is a Carprofen impurity also used in electrical materials

Definition

A white crystalline compound used in the manufacture of dyestuffs.

Definition

carbazole: A white crystalline compoundfound with anthracene,C₁₂H₉N; m.p. 238°C; b.p. 335°C. It isused in the manufacture of dyestuffs.

What are the applications of Application

Carbazole can be used to produce dyes, pigments, photoconductors, photosensitive materials, special inks, etc. The pigment produced with it is permanent purple RL, which is widely used in the coloring of automobile topcoat and high temperature resistant plastics, and has the advantages of high temperature resistance and ultraviolet light resistance. The dyestuffs sulphur vat blue RNX and Haichang blue produced with it have excellent fastness indicators, especially the fastness to chlorine bleaching. The blue varieties include carbazole IDM, carbazole LR, carbazole LB, and carbazole L3B. , the black varieties have carbazole black D. It also produces carbazole bisoxazine violet, a blue-violet pigment used in coatings, printing inks, carbon paper, and more. Carbazole is used in the production of sulfide reduced blue RNX, direct lightfast blue FFRL, FFGL, etc. It can also make leather, N-vinylcarbazole plastics, pesticides and insecticides tetranitrocarbazole, chlorinated carbazole, and UV-sensitive photographic dry films. In addition, carbazole has been increasingly used in the development of emerging optoelectronic new materials. The use of carbazole can prepare organic nonlinear optics (NLO) materials, organic electroluminescence (OEL) materials, photorefractive materials, containing Bifunctional system of carbazole chromophore, carbazole-containing photorefractive small molecular glass, etc.

Synthesis Reference(s)

Tetrahedron Letters, 14, p. 761, 1973 DOI: 10.1016/S0040-4039(01)95705-3

General Description

White crystals, plates, leaflets or light tan powder. Sublimes readily. Exhibits strong fluorescence and long phosphorescence on exposure to ultraviolet light.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Carbazole is an extremely weak base. Carbazole is incompatible with strong oxidizing agents. Carbazole reacts with nitrogen oxides. Potassium hydroxide fusion yields a salt.

Hazard

Possible carcinogen.

Fire Hazard

Flash point data for Carbazole are not available; however, Carbazole is probably combustible.

Safety Profile

intraperitoneal route. A flammable liquid.

Solubility in organics

Very weak alkaline. Slightly soluble in ethanol, ether and benzene, soluble in quinoline, pyridine and acetone, slightly soluble in cold benzene, glacial acetic acid, chloroform, carbon disulfide and gasoline, soluble in concentrated sulfuric acid without decomposition, slightly soluble in petroleum ether, chlorinated hydrocarbons and acetic acid.

Purification Methods

Dissolve carbazole (60g) in conc H2SO4 (300mL), extract with three 200mL portions of *benzene, then stir this into 1600mL of an ice-water mixture. The precipitate is filtered off, washed with a little water, dried, recrystallised from *benzene and then from pyridine/*benzene [Feldman et al. J Am Chem Soc 73 4341 1951]. It has also been recrystallised from EtOH or toluene, sublimed in vacuum, zone-refined, and purified by TLC. [UV: Armarego in Physical Methods in Heterocyclic Chemistry (Ed Katritzky, Academic Press) Vol III 158 1971, Beilstein 20/8 V 9.]