Tetralin


Tetralin is a hydrocarbon having the chemical formula C10H12. It is a partially hydrogenated derivative of naphthalene. It is a colorless liquid that is used as a hydrogen-donor solvent.

Production

Tetralin is produced by the catalytic hydrogenation of naphthalene.
Although nickel catalysts are traditionally employed, many variations have been evaluated. Over hydrogenation converts tetralin into octahydronaphthalene. Rarely encountered is dihydronaphthalene.

Laboratory methods

In a classic named reaction called the Darzens tetralin synthesis, named for Auguste Georges Darzens, derivatives can be prepared by intramolecular electrophilic aromatic substitution reaction of a 1-aryl-4-pentene using concentrated sulfuric acid,

Uses

Tetralin is used as a hydrogen-donor solvent, for example in coal liquifaction. It functions as a source of H2, which is transferred to the coal. The partially hydrogenated coal is more soluble.
It has been used in sodium-cooled fast reactors as a secondary coolant to keep sodium seals around pump impellers solidified.
It is also used for the laboratory synthesis of HBr:
The facility of this reaction is in part a consequence of the moderated strength of the benzylic C-H bonds.

Safety

is 2.68 g/kg. Tetralin induces methemoglobinemia.