119-64-2

Production Methods

Tetralin is prepared by the catalytic hydrogenation of naphthalene or during acidic, catalytic hydrocracking of phenanthrene. At 700℃, tetralin yields tars that contain appreciable quantities of 3,4-benzopyrene (172a).

Synthesis Reference(s)

Journal of the American Chemical Society, 111, p. 314, 1989 DOI: 10.1021/ja00183a048Tetrahedron Letters, 12, p. 1853, 1971

Air & Water Reactions

Flammable.

Reactivity Profile

1,2,3,4-Tetrahydronaphthalene may react vigorously with strong oxidizing agents. May react exothermically with reducing agents to release hydrogen gas. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick 1979 p.151-154].

Hazard

Irritant to eyes and skin; narcotic in high concentration.

Health Hazard

Liquid may cause nervous disturbance, green coloration of urine, and skin and eye irritation

Carcinogenicity

In male and female F344/N and NBR rats exposed to tetralin at concentrations of 0, 30, 60, or 120 ppm, 6 h plus T90 (12 min) per day, 5 days per week for 105 weeks, there were slightly increased incidences of cortical renal tubule adenoma in male rats. The incidence of cortical renal tubule adenomawas also significantly increased in the 120 ppm group. Exposure of male and female B6C3F1 mice to tetralin at concentrations of 0, 30, 60, or 120 ppm, 6 h plus T90 (12 min) per day, 5 days per week for 105 weeks and additional groups of male and female mice to the same concentrations for 12 months led to increased incidence of hemangiosarcoma of the spleen in 120 ppm females (172b).

Purification Methods

Wash tetralin with successive portions of conc H2SO4 until the acid layer is no longer coloured, then wash it with aqueous 10% Na2CO3, and then distilled water. Dry (CaSO4 or Na2SO4), filter, reflux and fractionally distil it under under reduced pressure from sodium or BaO. It can also be purified by repeated fractional freezing. Bass [J Chem Soc 3498 1964] freed tetralin, purified as above, from naphthalene and other impurities by conversion to ammonium tetralin-6-sulfonate. Concentrated H2SO4 (150mL) is added slowly to stirred tetralin (272mL) which is then heated on a water bath for about 2hours for complete solution. The warm mixture, when poured into aqueous NH4Cl solution (120g in 400mL water), gives a white precipitate which, after filtering off, is crystallised from boiling water, washed with 50% aqueous EtOH and dried at 100o. Evaporation of its boiling aqueous solution on a steam bath removes traces of naphthalene. The pure salt (229g) is mixed with conc H2SO4 (266mL) and steam distilled from an oil bath at 165-170o. An ether extract of the distillate is washed with aqueous Na2SO4, and the ether is evaporated, prior to distilling the tetralin from sodium. Tetralin has also been purified via barium tetralin-6-sulfonate, conversion to the sodium salt and decomposed in 60% H2SO4 using superheated steam. [Beilstein 5 H 491, 5 III 1219, 5 IV 1388.]

General Description

1,2,3,4-Tetrahydronaphthalene (Tetralin) is a hydrogenated derivative of naphthalene, commonly used as a solvent and hydrogen donor in organic reactions. It participates in transfer hydrogenation processes, such as the selective hydrogenation of polycyclic aromatic hydrocarbons (e.g., anthracene and naphthacene) when catalyzed by molten antimony trichloride, forming dihydro derivatives without complete dehydrogenation to naphthalene. Additionally, Tetralin acts as a hydrogen donor in thermal decomposition reactions, where it facilitates reverse radical disproportionation in certain solvents, leading to varied product distributions. Its utility extends to synthetic applications, including Friedel-Crafts cyclizations, where it contributes to the formation of enantiopure tetrahydronaphthalene derivatives.

Definition

ChEBI: An ortho-fused bicyclic hydrocarbon that is 1,2,3,4-tetrahydro derivative of naphthalene.