Tetrahydrofuran (THF) is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers.[7] Being polar and having a wide liquid range, THF is a versatile solvent.

Preferred IUPAC name
Systematic IUPAC name
Other names
Butylene oxide
Cyclotetramethylene oxide
Diethylene oxide
Tetra-methylene oxide
3D model (JSmol)
Abbreviations THF
ECHA InfoCard 100.003.389
RTECS number
  • LU5950000
Molar mass 72.107 g·mol−1
Appearance Colorless liquid
Odor Ether-like[2]
Density 0.8876 g/cm3 at 20 °C, liquid [3]
Melting point −108.4 °C (−163.1 °F; 164.8 K)
Boiling point 66 °C (151 °F; 339 K) [4][3]
Vapor pressure 132 mmHg (20 °C)[2]
1.4073 (20 °C) [3]
Viscosity 0.48 cP at 25 °C
1.63 D (gas)
Safety data sheet See: data page
Flammable (F)
Irritant (Xi)
R-phrases (outdated) R11, R19, R20/21/22, R36/37
S-phrases (outdated) S16, S29, S33
NFPA 704 (fire diamond)
Flash point −14 °C (7 °F; 259 K)
Explosive limits 2–11.8%[2]
Lethal dose or concentration (LD, LC):
  • 1650 mg/kg (rat, oral)
  • 2300 mg/kg (mouse, oral)
  • 2300 mg/kg (guinea pig, oral)[5]
21000 ppm (rat, 3 h)[5]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 200 ppm (590 mg/m3)[2]
REL (Recommended)
TWA 200 ppm (590 mg/m3) ST 250 ppm (735 mg/m3)[2]
IDLH (Immediate danger)
2000 ppm[2]
Related compounds
Related heterocycles
Related compounds
Diethyl ether
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Phase behaviour
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references


About 200,000 tonnes of tetrahydrofuran are produced annually.[8] The most widely used industrial process involves the acid-catalyzed dehydration of 1,4-butanediol. Ashland/ISP is one the biggest producers of this chemical route. The method is similar to the production of diethyl ether from ethanol. The butanediol is derived from condensation of acetylene with formaldehyde followed by hydrogenation.[7] DuPont developed a process for producing THF by oxidizing n-butane to crude maleic anhydride, followed by catalytic hydrogenation.[9] A third major industrial route entails hydroformylation of allyl alcohol followed by hydrogenation to 1,4-butanediol.

Other methods

THF can also be synthesized by catalytic hydrogenation of furan.[10][11] Certain sugars can be converted to THF, although this method is not widely practiced. Furan is thus derivable from renewable resources.



In the presence of strong acids, THF converts to a linear polymer called poly(tetramethylene ether) glycol (PTMEG), also known as polytetramethylene oxide (PTMO):

n C4H8O → −(CH2CH2CH2CH2O)n

This polymer is primarily used to make elastomeric polyurethane fibers like Spandex.[12]

As a solvent

The other main application of THF is as an industrial solvent for polyvinyl chloride (PVC) and in varnishes.[7] It is an aprotic solvent with a dielectric constant of 7.6. It is a moderately polar solvent and can dissolve a wide range of nonpolar and polar chemical compounds.[13] THF is water-miscible and can form solid clathrate hydrate structures with water at low temperatures.[14]

THF has been explored as a miscible co-solvent in aqueous solution to aid in the liquefaction and delignification of plant lignocellulosic biomass for production of renewable platform chemicals and sugars as potential precursors to biofuels.[15] Aqueous THF augments the hydrolysis of glycans from biomass and dissolves the majority of biomass lignin making it a suitable solvent for biomass pretreatment.

THF is often used in polymer science. For example, it can be used to dissolve polymers prior to determining their molecular mass using gel permeation chromatography. THF dissolves PVC as well, and thus it is the main ingredient in PVC adhesives. It can be used to liquefy old PVC cement and is often used industrially to degrease metal parts.

THF is used as a component in mobile phases for reversed-phase liquid chromatography. It has a greater elution strength than methanol or acetonitrile, but is less commonly used than these solvents.

THF is used as a solvent in 3D printing when using PLA plastics. It can be used to clean clogged 3D printer parts, as well as when finishing prints to remove extruder lines and add a shine to the finished product.

Laboratory use

In the laboratory, THF is a popular solvent when its water miscibility is not an issue. It is more basic than diethyl ether[16] and forms stronger complexes with Li+, Mg2+, and boranes. It is a popular solvent for hydroboration reactions and for organometallic compounds such as organolithium and Grignard reagents.[17] Thus, while diethyl ether remains the solvent of choice for some reactions (e.g., Grignard reactions), THF fills that role in many others, where strong coordination is desirable and the precise properties of ethereal solvents such as these (alone and in mixtures and at various temperatures) allows fine-tuning modern chemical reactions.

Commercial THF contains substantial water that must be removed for sensitive operations, e.g. those involving organometallic compounds. Although THF is traditionally dried by distillation from an aggressive desiccant, molecular sieves are superior.[18]

Drying of THF
Drying agentDuration of dryingWater content
None0 hours108 ppm
Sodium/benzophenone48 hours43 ppm
3 Å molecular sieves (20% by volume)72 hours4 ppm


THF is a weak Lewis base that forms molecular complexes with many transition metal halides. Typical complexes are of the stoichiometry MCl3(THF)3.[20] Such compounds are widely used reagents.

In the presence of a solid acid catalyst, THF reacts with hydrogen sulfide to give tetrahydrothiophene.[21]


THF is a relatively nontoxic solvent, with the median lethal dose (LD50) comparable to that for acetone. Reflecting its remarkable solvent properties, it penetrates the skin, causing rapid dehydration. THF readily dissolves latex and is typically handled with nitrile or neoprene rubber gloves. It is highly flammable.

One danger posed by THF follows from its tendency to form highly explosive peroxides on storage in air.

To minimize this problem, commercial samples of THF are often inhibited with butylated hydroxytoluene (BHT). Distillation of THF to dryness is avoided because the explosive peroxides concentrate in the residue.

See also


  1. "New IUPAC Organic Nomenclature - Chemical Information BULLETIN" (PDF).
  2. NIOSH Pocket Guide to Chemical Hazards. "#0602". National Institute for Occupational Safety and Health (NIOSH).
  3. Baird, Zachariah Steven; Uusi-Kyyny, Petri; Pokki, Juha-Pekka; Pedegert, Emilie; Alopaeus, Ville (6 Nov 2019). "Vapor Pressures, Densities, and PC-SAFT Parameters for 11 Bio-compounds". International Journal of Thermophysics. 40 (11): 102. doi:10.1007/s10765-019-2570-9.
  4. NIST Chemistry WebBook. http://webbook.nist.gov
  5. "Tetrahydrofuran". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  6. "New Environment Inc. - NFPA Chemicals". Newenv.com. Retrieved 2016-07-16.
  7. Müller, Herbert. "Tetrahydrofuran". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_221.
  8. Karas, Lawrence; Piel, W. J. (2004). "Ethers". Kirk‑Othmer Encyclopedia of Chemical Technology. John Wiley & Sons.
  9. Budavari, Susan, ed. (2001), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (13th ed.), Merck, ISBN 0911910131
  10. Morrison, Robert Thornton; Boyd, Robert Neilson (1972). Organic Chemistry (2nd ed.). Allyn and Bacon. p. 569.
  11. Starr, Donald; Hixon, R. M. (1943). "Tetrahydrofuran". Organic Syntheses.; Collective Volume, 2, p. 566
  12. Pruckmayr, Gerfried; Dreyfuss, P.; Dreyfuss, M. P. (1996). "Polyethers, Tetrahydrofuran and Oxetane Polymers". Kirk‑Othmer Encyclopedia of Chemical Technology. John Wiley & Sons.
  13. "Chemical Reactivity". Michigan State University. Archived from the original on 2010-03-16. Retrieved 2010-02-15.
  14. "NMR–MRI study of clathrate hydrate mechanisms" (PDF). Fileave.com. Archived from the original (PDF) on 2011-07-11. Retrieved 2010-02-15.
  15. Cai, Charles; Zhang, Taiying; Kumar, Rajeev; Wyman, Charles (13 August 2013). "THF co-solvent enhances hydrocarbon fuel precursor yields from lignocellulosic biomass". Green Chemistry. 15: 3140–3145. doi:10.1039/C3GC41214H.
  16. Lucht, B. L.; Collum, D. B. (1999). "Lithium Hexamethyldisilazide: A View of Lithium Ion Solvation through a Glass-Bottom Boat". Accounts of Chemical Research. 32: 1035–1042. doi:10.1021/ar960300e.
  17. Elschenbroich, C.; Salzer, A. (1992). Organometallics: A Concise Introduction (2nd ed.). Weinheim: Wiley-VCH. ISBN 3-527-28165-7.
  18. Williams, D. B. G.; Lawton, M. (2010). "Drying of Organic Solvents: Quantitative Evaluation of the Efficiency of Several Desiccants". Journal of Organic Chemistry. 75: 8351. doi:10.1021/jo101589h. PMID 20945830.
  19. F.A.Cotton, S.A.Duraj, G.L.Powell, W.J.Roth (1986). "Comparative Structural Studies of the First Row Early Transition Metal(III) Chloride Tetrahydrofuran Solvates". Inorg. Chim. Acta. 113: 81. doi:10.1016/S0020-1693(00)86863-2.CS1 maint: uses authors parameter (link)
  20. Manzer, L. E. "Tetrahydrofuran Complexes of Selected Early Transition Metals," Inorganic Synthesis. 21, 135–140, (1982).
  21. Swanston, Jonathan. "Thiophene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_793.pub2.

General reference

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