669-78-3

Basic information

• Product Name: difluoromaleic anhydride
• Synonyms: difluoromaleic anhydride;3,4-difluorofuran-2,5-dione
• CAS NO: 669-78-3
• Molecular Formula: C₄F₂O₃
• Molecular Weight: 134.04
• Mol File: 669-78-3.mol
• Article Data: 5

Chemical Properties

• Melting Point: 20 °C
• Boiling Point: 129.7°C at 760 mmHg
• Flash Point: 32.2°C
• Appearance: /
• Density: 1.66g/cm³
• Vapor Pressure: 10.1mmHg at 25°C
• Refractive Index: 1.416
• CAS DataBase Reference: difluoromaleic anhydride(CAS DataBase Reference)
• NIST Chemistry Reference: difluoromaleic anhydride(669-78-3)
• EPA Substance Registry System: difluoromaleic anhydride(669-78-3)

Safety Data

• Hazardous Substances Data: 669-78-3(Hazardous Substances Data)

Usage

Uses

Used in Organic Chemistry:
Difluoromaleic anhydride is used as a reagent for the synthesis of various organic compounds due to its strong electrophilic nature and ability to react with a variety of nucleophiles.
Used in Pharmaceutical Production:
Difluoromaleic anhydride is used as a key intermediate in the production of pharmaceuticals, leveraging its versatile reactivity to introduce fluorine atoms into organic molecules, which can enhance the properties and efficacy of the resulting drugs.
Used in Agrochemicals:
In the agrochemical industry, difluoromaleic anhydride is used as a building block for the synthesis of various agrochemicals, contributing to the development of more effective and environmentally friendly products.
Used in Polymer Chemistry:
Difluoromaleic anhydride is used as a monomer in polymer chemistry, taking advantage of its unique ability to react with dienes to create novel polymeric materials with specific properties.
Used in Materials Science:
In materials science, difluoromaleic anhydride is utilized in the development of new materials with tailored properties, such as improved thermal stability, chemical resistance, or specific optical characteristics, by incorporating fluorine atoms into their molecular structure.

InChI:InChI=1/C4F2O3/c5-1-2(6)4(8)9-3(1)7

Upstream product

• 664-66-4 2,2,3-trifluorosuccinic acid 
• 24849-02-3 perfluoro-2,5-dihydrofuran 
• 121-43-7 Trimethyl borate 

Downstream Products

• 782-90-1 (E)-2,3-Difluoro-3-phenylcarbamoyl-acrylic acid 
• 119767-75-8 benzyl hydrogen difluoromaleate 
• 114223-78-8 2,3-difluoro-N-phenyl-maleamic acid 
• 726-12-5 N-(4-chloro-phenyl)-2,3-difluoro-maleamic acid 

Relevant articles and documents

Hydrogen-bond symmetry in difluoromaleate monoanion

The symmetry of the hydrogen bond in hydrogen difluoromaleate monoanion is probed by X-ray crystallography and by the NMR method of isotopic perturbation in water, in two aprotic organic solvents, and in an isotropic liquid crystal. The X-ray crystal structure of potassium hydrogen difluoromaleate shows a remarkably short O-O distance of 2.41 A and equal O-H distances of 1.206 A, consistent with a strong and symmetric hydrogen bond. Incorporation of 18O into one carboxyl group allows investigation of the symmetry of the H-bond in solution by the method of isotopic perturbation. The 19F NMR spectra of the mono-18O-substituted monoanion in water, CD2Cl2, and CD3CN show an AB spin system, corresponding to fluorines in different environments. The difference is attributed to the perturbation of the acidity of a carboxylic acid by 18O, not to the mere presence of the 18O, because the mono-18O dianion shows equivalent fluorines. Therefore, it is concluded that the monoanion exists as an equilibrating pair of interconverting tautomers and not as a single symmetric structure not only in water but also in organic solvents. However, in the isotropic liquid crystal phase of 4-cyanophenyl 4-heptylbenzoate, tetrabutylammonium hydrogen difluoromaleate- 18O shows equivalent fluorines, consistent with a single symmetric structure. These results support earlier studies, which suggested that the symmetry of hydrogen bonds can be determined by the local environment.

Molecular structure of 3,4-difluorofuran-2,5-dione (difluoromaleic anhydride) as determined by electron diffraction and microwave spectroscopy in the gas phase and by theoretical computations

The structure of 3,4-difluorofuran-2,5-dione has been determined experimentally in the gas phase by microwave spectroscopy using rotation constants derived from five isotopomers and by a combined analysis of electrondiffraction and microwave data. The geometry is planar with C2v symmetry. Structural parameters [distances (rαo)/pm, angles a/deg, (1α errors)] for the combined analysis are: r(C=O) = 119.0(1); r(C-F) = 130.9(2); r(C=C) = 133.2(3); r(O-C) = 139.3(1); KC-C) = 148.5(2); C-C=C = 108.3(1); ZC=C-F = 129.9-(1); C-C=O = 129.3(1); C-O-C = 108.9(1); O-C-C = 107.2(1). These values are in excellent agreement with those obtained in an ab initio study of the molecular geometry at the MP2/6-311+G (2df) level of theory. The dipole moment of difluoromaleic anhydride has been determined experimentally by Starkeffect measurements to be 1.867(3) D.

Process for the preparation of difluoromaleic anhydride

A process for producing difluoromaleic anhydride by reacting sulfur trioxide with a fluorinated precursor selected from the group consisting of hexafluoro-2,5-dihydrofuran, hexafluoro-2,5-dihydrothiophene, difluoro-2,5-dihydrothiophene-2,5-dione and tetrafluoro-2,5-dihydrothiophene-2-one. Also disclosed are the compounds difluoro-2,5-dihydrothiophene-2,5-dione and tetrafluoro-2,5-dihydrothiophene-2-one. Difluoromaleic anhydride is useful for example as a component of fluoropolymers.

AN ABBREVIATED ROUTE TO DIFLUOROMALEIC ANHYDRIDE

Difluoromaleic anhydride is obtained in good yield by reaction of either hexafluoro-2,5-dihydrofuran or hexafluoro-2,5-dihydrothiophene with sulfur trioxide.Hexafluoro-2,5-dihydrothioyphene is prepared from sulfur and commercially available hexafluorocyclobutene, so its conversion to difluoromaleic anhydride in one step makes the latter readily available as well.