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In chemical engineering, azeotropic distillation usually refers to the specific technique of adding another component to generate a new, lower-boiling azeotrope that is heterogeneous (e.g. producing two, immiscible liquid phases), such as the example below with the addition of benzene to water and ethanol.
Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C 6 H 5 Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals. [6]
Halogenation of benzene where X is the halogen, catalyst represents the catalyst (if needed) and HX represents the protonated base. A few types of aromatic compounds, such as phenol, will react without a catalyst, but for typical benzene derivatives with less reactive substrates, a Lewis acid is required as a catalyst.
DDQ and an acid catalyst has been used to synthesise a steroid with a phenanthrene core by oxidation accompanied by a double methyl migration. [9] In the process, DDQ is itself reduced into an aromatic hydroquinone product. Sulfur and selenium are traditionally used in aromatization, the leaving group being hydrogen sulfide. [10]
In commercial applications, the alkylating agents are generally alkenes, some of the largest scale reactions practiced in industry.Such alkylations are of major industrial importance, e.g. for the production of ethylbenzene, the precursor to polystyrene, from benzene and ethylene and for the production of cumene from benzene and propene in cumene process:
Trimethylsilyl, tert-butyl, and isopropyl groups can form stable carbocations, hence are ipso directing groups. Meso-substitution refers to the substituents occupying a benzylic position. It is observed in compounds such as calixarenes and acridines. Peri-substitution occurs in naphthalenes for substituents at the 1 and 8 positions. [citation ...
The Blanc chloromethylation (also called the Blanc reaction) is the chemical reaction of aromatic rings with formaldehyde and hydrogen chloride to form chloromethyl arenes. The reaction is catalyzed by Lewis acids such as zinc chloride. [1] The reaction was discovered by Gustave Louis Blanc (1872-1927) in 1923. [2] [3]
The sensitivity of catalytic reforming to contamination by sulfur and nitrogen requires hydrotreating the naphtha before it enters the reformer, adding to the cost and complexity of the process. Dehydrogenation, an important component of reforming, is a strongly endothermic reaction, and as such, requires the reactor vessel to be externally heated.