| 词条 | Diglycolic acid |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 424666297 | ImageFile=Diglycolic acid.png | ImageSize=200px | ImageFile1=Diglycolic acid 3D.png | ImageSize1=200px | IUPACName=2-(carboxymethyloxy)acetic acid | OtherNames= |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|??}} | CASNo= 110-99-6 | PubChem=8088 | SMILES=C(C(=O)O)OCC(=O)O | EINECS = 203-823-5 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 7797 | InChI = 1/C4H6O5/c5-3(6)1-9-2-4(7)8/h1-2H2,(H,5,6)(H,7,8) | InChIKey = QEVGZEDELICMKH-UHFFFAOYAA | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C4H6O5/c5-3(6)1-9-2-4(7)8/h1-2H2,(H,5,6)(H,7,8) | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = QEVGZEDELICMKH-UHFFFAOYSA-N }} |Section2={{Chembox Properties | Formula=C4H6O5 | MolarMass=134.09 g/mol | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = }} }}Diglycolic acid is an aliphatic dicarboxylic acid, its acidity is between the one of acetic acid and oxalic acid.[1] It is formed in the oxidation of diethylene glycol in the body and can lead to severe complications with fatal outcome.[2] PreparationOxidation of diethylene glycol with concentrated nitric acid was described by A. Wurtz in 1861[3] In parallel, W. Heintz reported the synthesis of diglycolic acid from chloroacetic acid by heating with sodium hydroxide solution.[4] In a version with barium hydroxide solution as an alkaline medium, diglycolic acid is obtained in 68% yield after acidification.[5] The yields of the described reactions are unsatisfactory for use on a technical scale. The single-stage nitric acid process gives even in the presence of an oxidation catalyst (vanadium(V)oxide) yields of only 58-60%.[6] In a multi-stage process of nitric acid oxidation at 70 °C and multiple crystallization steps, evaporation of the residues and return of the diethylene glycol-containing mother liquor, product yields of up to 99% (based on diethylene glycol) can be achieved.[7] The oxidation of diethylene glycol with air, oxygen or ozone avoids the use of expensive nitric acid and prevents the inevitable formation of nitrous gases.[8] In the presence of a platinum catalyst, yields of 90% can be obtained by air oxidation.[9] On a bismuth platinum contact catalyst, yields of 95% are to be achieved under optimized reaction conditions.[10] The oxidation of 1,4-dioxan-2-one (p-dioxanone, a lactone which is used as a comonomer in biodegradable polyesters with nitric acid or dinitrogen tetroxide) is also described with yields of up to 75%.[11] PropertiesDiglycolic acid is readily water soluble and crystallizes from water in monoclinic prisms as a white, odorless solid. At an air humidity of more than 72% and 25 °C the monohydrate is formed. The commercial product is the anhydrous form as a free-flowing flakes.[12] ApplicationDiesters of diglycolic acid with (branched) higher alcohols can be used as softeners for polyvinyl chloride (PVC) with comparable properties as di-n-octyl phthalate (DOP).[13] Basic solutions of diglycolic acid are described for the removal of limescale deposits in gas and oil bores, as well as in systems such as heat exchangers or steam boilers.[14] Diglycolic acid can be used as a diester component in homo- and copolymeric polyesters (so-called polyalkylene diglycolates) which are biocompatible and biodegradable and can be used alone or in blends with aliphatic polyesters as tissue adhesives, cartilage substitutes or as implant materials:[15] References1. ^{{citation|editor-surname1= L. Bhattacharyya, J. Rohrer|title=Appendix 1: DISSOCIATION CONSTANTS (pKa) OF ORGANIC ACIDS (AT 20 °C), in Applications of Ion Chromatography for Pharmaceutical and Biological Products|publisher=John Wiley & Sons, Inc.|date=2012|doi=10.1002/9781118147009.app1}} 2. ^{{citation|surname1=A.A. Roscher, E. Jussek, T. Noguchi, S. Franklin|periodical=Bull. Soc. Pharm. Environ. Pathol.|title=Fatal Accidental Diglycolic Acid Intoxication|volume=III|issue=4|date=1975|url=PDF}} 3. ^{{citation|surname1=A. Wurtz|periodical=Liebigs Ann. Chem.|title=Umwandlung des Aethylens zu complicirten organischen Säuren|volume=117|issue=1|pages=136–140|date=1861|language=German|doi=10.1002/jlac.18611170114}} 4. ^{{citation|surname1=W. Heintz|periodical=Ann. Phys.|title=Ueber die Diglycolsäure (Paraäpfelsäure)|volume=191|issue=2|pages=280–295|date=1862|language=German|doi=10.1002/andp.18621910206}} 5. ^{{citation|surname1=K.E. Füger|title=Synthese und katalytische Reduktion von Glykolsäure und Glykolsäureestern, Promotionsarbeit ETH Zürich|publisher=Juris-Verlag|date=1959|language=German|url=PDF}} 6. ^{{citation|surname1=C. Erk|periodical=Liebigs Ann. Chem.|title=Condensation of diglycolic acid dichloride with polyglycols, 5. An improved synthesis of cyclic polyether-esters by cyclization|volume=10|pages=1083–1084|date=1991|doi=10.1002/jlac.1991199101186}} 7. ^{{Cite patent|country = US|number =4066691 |Code= |title =Process for the production of pure diglycolic acid by oxidation if diethylene glycol with nitric acid |V-Datum =1978-1-3 |A-Datum =1976-9-8 |Erfinder =M. Schröder |Anmelder=Chemische Werke Hüls AG}} 8. ^{{Cite patent|country = US|number =3879452 |Code= |title =Method for making diglycolic acid, dipropionic acid and the salts thereof |V-Datum =1975-4-22 |A-Datum =1971-6-18 |Erfinder =G.E. Brown, Jr. |Anmelder=Conen Corp.}} 9. ^{{Cite patent|country = US|number =4256916 |Code=A |title =Oxidation of polyethylene glycols to dicarboxylic acids|V-Datum =1981-3-17 |A-Datum =1979-8-15 |Erfinder =D.L. Morris, W.J. Gammans, J.D. Holmes |Anmelder=Eastman Kodak Co.}} 10. ^{{citation|surname1=Y-Y. Zhang, Z.-Y. Liang, Y.-D. Zhang|periodical=Fine Chemicals|title=Preparation of Diglycolic Acid via Oxidation of Diethylene Glycol with Molecular Oxygen|date=May 2012|url=PDF}} 11. ^{{Cite patent|country = US|number =3952054 |Code= |title =Process for preparing diglycolic acid|V-Datum =1976-4-20 |A-Datum =1974-12-5 |Erfinder =C.Y. Shen |Anmelder=Monsanto Co.}} 12. ^{{citation|surname1=W.M. Bruner, L.T. Sherwood, Jr.|periodical=Ind. Eng. Chem.|title=Diglycolic acid – a new commercial dibasic acid|volume=41|issue=8|pages=1653–1656|date=1949|doi=10.1021/ie50476a032}} 13. ^{{Cite patent|country = US|number =3173888 |Code= |title =Diesters of diglycolic acid and vinyl chloride polymers plastized therewith|V-Datum =1965-3-16 |A-Datum =1962-11-13 |Erfinder =P.T. von Bramer, R.M. Simons |Anmelder=Eastman Kodak Co.}} 14. ^{{Cite patent|country = US|number =3639279 |Code= |title =Scale removal composition and method using salt of diglycolic acid and base at pH above 5|V-Datum =1972-2-1 |A-Datum =1969-4-1 |Erfinder =T.R. Gardner, R.M. Lasater, J.A. Knox |Anmelder=Halliburton Co.}} 15. ^{{Cite patent|country = US|number =5696178 |Code= |title =Absorbable polyalkylene diglycolates|V-Datum =1997-12-9 |A-Datum =1996-7-22 |Erfinder =K. Cooper, A. Scopelianos |Anmelder=Ethicon, Inc.}} 2 : Dicarboxylic acids|Ethers |
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