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Topic: Tetrahydrofuran


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THF

In the News (Sun 16 Jun 19)

  
  Process for the preparation of tetrahydrofuran - Patent 4271081
Tetrahydrofuran is prepared by reacting a 1,4-dihalobutane such as 1,4-dichlorobutane with water in the presence of a strong acid.
Tetrahydrofuran is a cyclic ether finding wide and substantial use as a solvent for natural and synthetic resins, especially the vinyl resins, in coatings, adhesives, printing inks, as a chemical intermediate and as a monomer.
Tetrahydrofuran has been prepared via the catalytic hydrogenation of furan, from the reaction of acetylene and formaldehyde and from the dehydrocyclization of 1,4-butanediol or dehydrochlorocyclization of 4-chloro-1-butanol.
www.freepatentsonline.com /4271081.html   (1765 words)

  
 Multi-step process for preparation of tetrahydrofuran starting from propylene, oxygen and a carboxylic acid - Patent ...
It is known in the art that tetrahydrofuran may be made by a number of different methods; the more prominent methods are by the catalytic hydrogenation of furan or by the dehydration of 1,4-butanediol.
In practice, the tetrahydrofuran is most often produced by a series of reactions starting with the reaction of formaldehyde and acetylene in the presence of a cuprous acetylide complex to form butynediol.
In carrying out the preparation of tetrahydrofuran starting from propylene, oxygen and a carboxylic acid, the procedures disclosed in copending applications A and B may be used to obtain the carboxylic acid esters of 1,4-butanediol.
www.freepatentsonline.com /4005113.html   (2841 words)

  
 Tetrahydrofuran
Effects on Humans: Tetrahydrofuran is a central nervous system depressant in humans; based on effects seen in animals, it may also cause irritation of the mucous membranes and upper respiratory tract and liver and kidney damage.
Before a worker is placed in a job with a potential for exposure to tetrahydrofuran, the examining physician should evaluate and document the worker's baseline health status with thorough medical, environmental, and occupational histories, a physical examination, and physiologic and laboratory tests appropriate for the anticipated occupational risks.
Tetrahydrofuran also may be disposed of in an organometallic or organic lab pack that meets the requirements of 40 CFR 264.316 or 265.316.
www.osha.gov /SLTC/healthguidelines/tetrahydrofuran/recognition.html   (4363 words)

  
 NTP: Abstract for TR-475 - Tetrahydrofuran
Tetrahydrofuran is also an indirect food additive when it is in contact with the surface of articles intended for use in food processing.
Tetrahydrofuran was nominated for study because of the potential for occupational exposure in humans.
The incidences of renal tubule epithelial adenoma or carcinoma (combined) in exposed males occurred with a positive trend, and the incidences in 600 and 1,800 ppm males exceeded the historical range for chamber controls in 2-year NTP inhalation studies.
ntp-server.niehs.nih.gov /ntpweb/index.cfm?objectid=070A9D22-E84D-DE39-30BD9F0AA6E1794C   (1308 words)

  
 Synthesis of tetrahydrofuran polymers using calcined silica-alumina or beaching earth catalysts - Patent 5210283
Tetrahydrofuran is polymerized in the presence of a carboxylic acid anhydride and a solid acid catalyst that has been calcined at a temperature greater than about 600.degree.
A process for producing a tetrahydrofuran polymer, said process comprising polymerizing tetrahydrofuran in the presence of a carboxylic acid anhydride and an effective amount of a solid acid catalyst selected from the group consisting of amorphous silica-aluminas and acid-washed bleaching earths, wherein the catalyst is calcined at a temperature greater than about 600.degree.
In the process of the invention, a tetrahydrofuran polymer having a relatively narrow molecular weight distribution is produced by polymerizing THF and optionally other monomers in the presence of a carboxylic acid anhydride and a calcined solid acid catalyst selected from the group consisting of amorphous silica-alumina and acid-washed bleaching earths.
www.freepatentsonline.com /5210283.html   (3470 words)

  
 T.O.M. Report No. 13 Synthetic Lubricating Oils From Tetrahydrofuran, Additive for Break-In Oil and Recoil Fluid at ...
The ability of tetrahydrofuran to polymerize in the presence of oxonium salts was discovered by h.
The ratio of tetrahydrofuran to ethyene oxide is 4:1 for the manufacture of M586.
The unreacted tetrahydrofuran is distilled off, phenol and caustic are added to the polymerizate and the mixture is heated to 165º C. until no organic chlorine can be detected.
www.fischer-tropsch.org /Bureau_of_Mines/reports/tom_rpt_13.htm   (1703 words)

  
 Tetrahydrofuran - Wikipedia
Tetrahydrofuran ist ein organisches Lösungsmittel und gehört zur Stoffklasse der (cyclischen) Ether.
Tetrahydrofuran ist eine farblose, brennbare Flüssigkeit mit etherartigem Geruch.
Tetrahydrofuran, auch bekannt unter dem Namen Tangit®, wird als Lösungsmittel für PVC, Polystyrol, Polyurethane, Cellulosenitrat, Klebstoffe und Lacke verwendet; es ist ein Zwischenprodukt bei der Polyamid-, Polyester- und Polyurethan-Herstellung, und es dient zur Gewinnung von Tetrahydrothiophen und Pyrrolidin.
de.wikipedia.org /wiki/Tetrahydrofuran   (147 words)

  
 Lyondell Chemical Company Products And Services - Tetrahydrofuran (THF)
Tetrahydrofuran (THF) is a clear, colorless, low-viscosity liquid with an ether-like odor.
The vapor of tetrahydrofuran is highly irritating to the eyes of human subjects.
The intent of this information is to inform personnel who handle or may be exposed to tetrahydrofuran of the properties and hazards associated with the compound.
www.lyondell.com /html/products/products/thf.shtml   (899 words)

  
 EWG Investigation | U.S. Tap Water Quality Database   (Site not responding. Last check: 2007-10-07)
Tetrahydrofuran is an intermediate in chemical manufacturing and a solvent for dyes and lacquers.
Potential health impacts associated with Tetrahydrofuran include cardiovascular or blood toxicity, developmental toxicity, endocrine toxicity, gastrointestinal or liver toxicity, neurotoxicity, and respiratory toxicity.
Under the federal tap water law, water suppliers are not required to routinely test for Tetrahydrofuran, and any level is legal in tap water.
www.ewg.org /tapwater/contaminants/contaminant.php?contamcode=2263   (343 words)

  
 Documentation for Immediately Dangerous to Life or Health Concentrations (IDLHs) - 109999
Therefore, 20,000 ppm has been chosen as the IDLH because it is the lower explosive limit (LEL) of tetrahydrofuran.
However, the revised IDLH is 2,000 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 2%).
Acute and repeated inhalation toxicity of tetrahydrofuran in laboratory animals.
www.cdc.gov /niosh/idlh/109999.html   (188 words)

  
 CYCLIC ALDEHYDE (FURFURAL)
It is used as a fungicide and weed killer.
Solvent is a substance, usually a liquid, that acts as a dissolving agent or that is capable of dissolving another substance.
BTX, carbon disulfide, diemthyl sulfoxide, carbon tetrachloride, chloroform, ether, tetrahydrofuran, furfural, hexane and turpentine.
www.chemicalland21.com /arokorhi/industrialchem/solalc/FURFURAL.htm   (1052 words)

  
 Tetrahydrofuran Vapor Monitor / Monitoring Badge - EMT
EMT's Tetrahydrofuran Monitoring Kit includes one monitoring badge, detailed instructions, a monitoring information form, and a shipping label.
They are designed to provide you with the ability to check exposure levels to Tetrahydrofuran.
OSHA Permissible exposure limit (PEL) for tetrahydrofuran is 200 ppm, 590 mg/m3
www.emt-online.com /ProductPages/Tetrahydrofuran.htm   (151 words)

  
 Safety and Health Topics: Tetrahydrofuran
Cartigny, B., et al.: 1H NMR spectroscopic investigation of serum and urine in a case of acute tetrahydrofuran poisoning.
Chhabra R.S., Herbert, R.A., Roycroft, J.H., Chou, B., Miller, R.A. and Renne, R.A.: Carcinogenesis studies of tetrahydrofuran vapors in rats and mice.
Food and Drug Administration: International Conference on Harmonization: final recommendations on the revision of the permitted daily exposures for two solvents, n-methylpyrrolidone and tetrahydrofuran, according to the maintenance procedures for the guidance Q3C Impurities: Residual Solvents; Availability.
www.osha.gov /dts/chemicalsampling/data/CH_271000.html   (451 words)

  
 TETRAHYDROFURAN
Synonyms: Diethylene oxide, oxacyclopentane; THF; tetrahydrofuran and stabilizer; 1,4-Epoxybutane; Butylene Oxide; Cyclotetramethylene Oxide; Furan, tetrahydro
Under the National Toxcology Program (NTP), the U.S. Public Health Service completed a 2-year (lifetime) inhalation study in rats and mice on Tetrahydrofuran (THF) which suggests that THF is a carcinogen in laboratory animals.
When released into the soil, this material is expected to leach into groundwater.
www.jtbaker.com /msds/englishhtml/t1222.htm   (1452 words)

  
 Equilibrium Constant and Enthalpy for the Hydrogen Bonding of Acetic Acid with Tetrahydrofuran in Supercritical CO2   (Site not responding. Last check: 2007-10-07)
Equilibrium Constant and Enthalpy for the Hydrogen Bonding of Acetic Acid with Tetrahydrofuran in Supercritical CO2
Equilibrium Constant and Enthalpy for the Hydrogen Bonding of Acetic Acid with Tetrahydrofuran in Supercritical CO Qun Xu, Buxing Han,* and Haike Yan
FTIR spectroscopy was used to study the hydrogen bonding of acetic acid and tetrahydrofuran in supercritical (SC) CO in the ranges of 100-160 bar and 308.15-323.15 K, and the concentration of tetrahydrofuran varied from 0 to 0.4 mol/L. The equilibrium constant K
pubs.acs.org /cgi-bin/abstract.cgi/jpcafh/1999/103/i27/abs/jp9900739.html   (214 words)

  
 Tetrahydrofuran - toxicity, ecologicial toxicity and regulatory information   (Site not responding. Last check: 2007-10-07)
Tetrahydrofuran - Identification, toxicity, use, water pollution potential, ecological toxicity and regulatory information
There may be other diseases and chemicals that have similar symptoms.
If the victim has collapsed or is unconscious, call 911.
www.pesticideinfo.org /Detail_Chemical.jsp?Rec_Id=PC34567   (753 words)

  
 Tetrahydrofuran, HPLC Grade, Chemistry Supplies and Laboratory Chemicals
Tetrahydrofuran, HPLC Grade, Chemistry Supplies and Laboratory Chemicals
O : F.W. Submicron filtered.!Packaged under inert gas.!Suitable for high performance liquid chromatography, ultraviolet spectrophotometry or general use.
The LAB DEPOT is your source for laboratory chemicals equipment and scientific supplies including Tetrahydrofuran, HPLC Grade, reagent chemicals, research products and lab test kits for water purification and pH sampling.
www.labdepotinc.com /Chemical_Details~pid~HP842.aspx   (146 words)

  
 A comprehensive comparison of DNA replication past 2-deoxyribose and its tetrahydrofuran analog in Escherichia coli -- ...
A comprehensive comparison of DNA replication past 2-deoxyribose and its tetrahydrofuran analog in Escherichia coli -- Kroeger et al.
A comprehensive comparison of DNA replication past 2-deoxyribose and its tetrahydrofuran analog in Escherichia coli
Structure of abasic lesions 2-deoxyribose (AP) and tetrahydrofuran (F).
nar.oxfordjournals.org /cgi/content/full/32/18/5480   (2773 words)

  
 Hydrates From Ice (HyFI), Results, Thermal Conductivity in Silt Saturated With Tetrahydrofuran (THF) Hydrate: Figure 1   (Site not responding. Last check: 2007-10-07)
Hydrates From Ice (HyFI), Results, Thermal Conductivity in Silt Saturated With Tetrahydrofuran (THF) Hydrate: Figure 1
With each stage, a phase change in the sample causes a shift in the measured thermal conductivity.
Porosity increases, cracks may form in our unconfined sample, and the thermal conductivity falls as a result.
woodshole.er.usgs.gov /operations/hi_fi/thf_silt/Figure1.html   (83 words)

  
 NTP: The National Toxicology Program
Page 2 NTP Experiment-Test: 05181-03 NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL Report: PEIRPT09 Study Type: CHRONIC TETRAHYDROFURAN Date: 02/20/96 Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 16:13:03 _____________________________________________________________________________________________________________________
Page 3 NTP Experiment-Test: 05181-03 NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL Report: PEIRPT09 Study Type: CHRONIC TETRAHYDROFURAN Date: 02/20/96 Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 16:13:03 _____________________________________________________________________________________________________________________
Page 4 NTP Experiment-Test: 05181-03 NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL Report: PEIRPT09 Study Type: CHRONIC TETRAHYDROFURAN Date: 02/20/96 Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 16:13:03 _____________________________________________________________________________________________________________________
ntp-server.niehs.nih.gov /index.cfm?objectid=03838DF7-9F9E-CE00-90B30FBFAD66139D   (1503 words)

  
 Studies toward (-)-Gymnodimine: Concise Routes to the Spirocyclic and Tetrahydrofuran Moieties   (Site not responding. Last check: 2007-10-07)
Studies toward (-)-Gymnodimine: Concise Routes to the Spirocyclic and Tetrahydrofuran Moieties
Herein we report the synthesis of the tetrahydrofuran fragment and a strategy toward the spirocyclic imine fragment of this family of toxins.
Key reactions include an asymmetric anti-aldol reaction to set the stereochemistry of the tetrahydrofuran and a formal, intermolecular Diels-Alder reaction involving an
pubs.acs.org /cgi-bin/abstract.cgi/orlef7/2000/2/i06/abs/ol005510c.html   (125 words)

  
 CiteULike: Formation of the aureothin tetrahydrofuran ring by a bifunctional cytochrome p450 monooxygenase.   (Site not responding. Last check: 2007-10-07)
CiteULike: Formation of the aureothin tetrahydrofuran ring by a bifunctional cytochrome p450 monooxygenase.
Formation of the aureothin tetrahydrofuran ring by a bifunctional cytochrome p450 monooxygenase.
Note: You or your institution must have access rights to this article.
www.citeulike.org /user/robert/article/500605   (60 words)

  
 tetrahydrofuran — Infoplease.com   (Site not responding. Last check: 2007-10-07)
3 000 T/A Tetrahydrofuran Unit Starts Production in Qiqihar.
PENN SPECIALTY.(Penn Specialty Chemicals Inc. raises off list prices for tetrahydrofuran, Polymeg)(Brief Article)
BASF to build new PolyTHF and THF plants in Shanghai.
www.infoplease.com /ce6/sci/A0919481.html   (103 words)

  
 Sodium Bis(trimethylsilyl)amide, 2.0 M Solution in Tetrahydrofuran
Chemical Catalog  » Alphabetical Listing of Chemicals  »; S  » Sodium Bis(trimethylsilyl)amide, 2.0 M Solution in Tetrahydrofuran
Please contact us for pricing or to place an order for this item.
[sodium bis(trimethylsilyl)amide, tetrahydrofuran, solution], 3, UN2924, PG II
www.sciencelab.com /page/S/PVAR/10426/SLS2899   (77 words)

  
 (WO/1992/002298) HYDROGENATION CATALYST AND METHOD FOR PREPARING TETRAHYDROFURAN   (Site not responding. Last check: 2007-10-07)
(WO/1992/002298) HYDROGENATION CATALYST AND METHOD FOR PREPARING TETRAHYDROFURAN
(FR) CATALYSEUR D'HYDROGENATION ET PROCEDE DE PREPARATION DE TETRAHYDROFURANE
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www.wipo.int /pctdb/en/wo.jsp?WO=1992/02298   (165 words)

  
 (WO/1991/015481) PROCESS FOR THE PREPARATION OF HIGH-PURITY TETRAHYDROFURAN   (Site not responding. Last check: 2007-10-07)
(WO/1991/015481) PROCESS FOR THE PREPARATION OF HIGH-PURITY TETRAHYDROFURAN
(FR) PROCEDE POUR PREPARER DU TETRAHYDROFURANE DE GRANDE PURETE
(EN) Disclosed is a process for the preparation of high-purity tetrahydrofuran from a mixture of 2,5-dihydrofuran and 3,4-epoxy-1-butene and/or crotonaldehyde wherein the mixture is hydrogenated in the presence of a nickel or platinum catalyst to obtain a product consisting essentially of tetrahydrofuran and 1-butanol which are readily separable.
www.wipo.int /pctdb/en/wo.jsp?WO=1991/15481   (178 words)

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