Description
Dibenzothiophene (DBT) is an organosulfur compound found in crude oil and petroleum. It is a colourless solid that is chemically somewhat similar to anthracene. Dibenzothiophene is used as a chemical intermediate in cosmetics and pharmaceuticals (NLM, 2006).It is used to investigate the effect of sulfur compounds in gasoline range during the fluid catalytic cracking (FCC) process.
Chemical Properties
White to light yellow crystal powder
History
Dibenzothiophene was first synthesized in 1870 by Stemhouse by heating biphenyl with iron scrap, but the assigned incorrect structure was corrected by Graebe. The natural dibenzothiophene was isolated from coal tar by Kruber. Besides this, various alkylated dibenzothiophenes have also been isolated from the crude oil, but it was difficult to desulfurize them catalytically. The presence of sulfur in the fuel produces sulfur dioxide when burnt and causes air pollution.
Dibenzothiophene is a thermally stable compound and resistant to mild oxidizing agents. Depending on the nature of the oxidizing agent it is oxidized to corresponding sulfoxide and sulfone. There are numerous protocols for the construction of dibenzothiophene but some of them are limited to the synthesis of specific compounds due to noncompatibility of functional groups.
Uses
Dibenzothiophene (DBT) can be used as:
- A starting material for the synthesis of corresponding sulfoxide and sulfone by oxidative desulfurization using various catalysts.
- A template for the synthesis of surface molecular imprinted polymer (SMIP). SMIP is applicable for the removal of dibenzothiophene during desulfurization of the gasoline
- A precursor for the synthesis of DBT based π-conjugating polymers.
Uses
Dibenzothiophene is used to investigate the effect of sulfur compounds in gasoline range during the fluid catalytic cracking (FCC) process.
Application
Dibenzothiophene is an important representative of polycyclic aromatic hydrocarbons (PAHs). Kinetics of hydrodesulfurization of dibenzothiophene on presulflded molybdenaalumina catalyst has been studied in a high-pressure-flow microreactor. Biodesulfurization of dibenzothiophene by selective cleavage of carbon sulphur bonds by a thermophilic bacterium Bacillus subtilis WU-S2B has been reported.
Dibenzothiophene was employed as heavy model sulfur compound to investigate the effect of heavy sulfur compounds on the percentage of sulfur in gasoline range during the Fluid Catalytic Cracking (FCC) process.
Definition
ChEBI: A mancude organic heterotricyclic parent that consists of a thiophene ring flanked by two benzene rings ortho-fused across the 2,3- and 4,5-positions.
Preparation
Dibenzothiophene is prepared by the reaction of biphenyl with sulfur dichloride in the presence of aluminium chloride.
Reactions
Reduction with lithium results in scission of one C-S bond. S-oxidation occurs to give the sulfone, which is more labile than the parent dibenzothiophene. With butyllithium, this heterocycle undergoes stepwise lithiation at the 4- and 6- positions.
General Description
Dibenzothiophene is an important representative of polycyclic aromatic hydrocarbons (PAHs). Kinetics of hydrodesulfurization of dibenzothiophene on presulflded molybdenaalumina catalyst has been studied in a high-pressure-flow microreactor. Biodesulfurization of dibenzothiophene by selective cleavage of carbon sulphur bonds by a thermophilic bacterium Bacillus subtilis WU-S2B has been reported.
Chemical Reactivity
Dibenzothiophene is heteroaromatic in nature and undergoes electrophilic substitution reactions smoothly. Mostly, electrophilic substitution occurs at position 2 of dibenzothiophene offering 2-substituted dibenzothiophene, provided position 2 is not preoccupied.
Purification Methods
Purify dibenzothiophene by chromatography on alumina with pet ether, in a darkened room. Recrystallise it from water or EtOH. [Beilstein 17 V 239.]
