Tetralin
Encyclopedia
Tetralin is a hydrocarbon
having the chemical formula
C10H12. This molecule
is similar to the naphthalene
chemical structure
except that one ring
is saturated
.
The compound
can be synthesized
in a Bergman cyclization
. In a classic named reaction called the Darzens tetralin synthesis (Auguste George Darzens (1867–1954), 1926) derivative
s can be prepared by intramolecular
ring-closing reaction of an 1-aryl-4-pentene with concentrated
sulfuric acid
, or simply through the hydrogenation
of naphthalene
in the presence of a platinum
catalyst.
A large amount of work has been devoted to the hydrogenation of naphthalene into tetralin. Mixture
s containing different proportion
s of naphthalene, tetralin, and decalin can be produced depending on the pressure
and temperature
of the process. Tetralin has been obtained from pressed naphthalene isolated
from coke tar by hydrogenating it over commercial catalyst WS2 + NiS + Al2O3 and CoO + MoO3 + Al2O3 under pressure of 50-300 atm. The extent to which naphthalene is hydrogenated at pressures up to 60-70 atm is determined by catalyst activity; it is maximum if CoO + MoO3 + Al2O3 or WS2 + NiS + Al2O3 catalyst are used at 300-370 °C.
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
having the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
C10H12. This molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
is similar to the naphthalene
Naphthalene
Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...
chemical structure
Chemical structure
A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...
except that one ring
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
is saturated
Saturation (chemistry)
In chemistry, saturation has six different meanings, all based on reaching a maximum capacity...
.
The compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
can be synthesized
Chemical synthesis
In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...
in a Bergman cyclization
Bergman cyclization
The Bergman cyclization or Bergman reaction or Bergman cycloaromatization is an organic reaction and more specifically a rearrangement reaction taking place when an enediyne is heated in presence of a suitable hydrogen donor . It is named for the American chemist Robert George Bergman...
. In a classic named reaction called the Darzens tetralin synthesis (Auguste George Darzens (1867–1954), 1926) derivative
Derivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...
s can be prepared by intramolecular
Intramolecular
Intramolecular in chemistry describes a process or characteristic limited within the structure of a single molecule, a property or phenomenon limited to the extent of a single molecule.- Examples :...
ring-closing reaction of an 1-aryl-4-pentene with concentrated
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
, or simply through the hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
of naphthalene
Naphthalene
Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...
in the presence of a platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
catalyst.
Production
Tetralin is produced by the catalytic hydrogenation of naphthalene.A large amount of work has been devoted to the hydrogenation of naphthalene into tetralin. Mixture
Mixture
In chemistry, a mixture is a material system made up by two or more different substances which are mixed together but are not combined chemically...
s containing different proportion
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
s of naphthalene, tetralin, and decalin can be produced depending on the pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
and temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
of the process. Tetralin has been obtained from pressed naphthalene isolated
Liquid-liquid extraction
Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. It is an extraction of a substance from one liquid phase into another liquid...
from coke tar by hydrogenating it over commercial catalyst WS2 + NiS + Al2O3 and CoO + MoO3 + Al2O3 under pressure of 50-300 atm. The extent to which naphthalene is hydrogenated at pressures up to 60-70 atm is determined by catalyst activity; it is maximum if CoO + MoO3 + Al2O3 or WS2 + NiS + Al2O3 catalyst are used at 300-370 °C.