652-18-6

Basic information

• Product Name: 2,3,5,6-Tetrafluorobenzoic acid
• Synonyms: 2,3,5,6-TETRAFLUOROBENZOIC ACID;RARECHEM AL BO 0266;2,3,5,6-Tetrafluorobenzoic acid,98%;4H-Tetrafluorobenzoic acid;Benzoic acid,2,3,5,6-tetrafluoro-
• CAS NO: 652-18-6
• Molecular Formula: C₇H₂F₄O₂
• Molecular Weight: 194.08
• EINECS: 416-800-1
• Product Categories: Benzoic acid
• Mol File: 652-18-6.mol

Chemical Properties

• Melting Point: 150-152 °C(lit.)
• Boiling Point: 227.9 °C at 760 mmHg
• Flash Point: 91.6 °C
• Appearance: White to almost white/Crystalline Powder
• Density: 1.5165 (estimate)
• Vapor Pressure: 0.0427mmHg at 25°C
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 1.66±0.10(Predicted)
• CAS DataBase Reference: 2,3,5,6-Tetrafluorobenzoic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3,5,6-Tetrafluorobenzoic acid(652-18-6)
• EPA Substance Registry System: 2,3,5,6-Tetrafluorobenzoic acid(652-18-6)

Safety Data

• Hazard Codes: Xi,C
• Statements: 38-41
• Safety Statements: 22-26-37/39
• WGK Germany: 1
• HazardClass: IRRITANT, CORROSIVE
• Hazardous Substances Data: 652-18-6(Hazardous Substances Data)

Usage

Uses

Used in Research and Development:
2,3,5,6-Tetrafluorobenzoic acid is used as a research chemical for various scientific investigations and experiments. Its unique chemical properties make it a valuable compound for exploring new chemical reactions, synthesizing novel compounds, and understanding the behavior of fluorinated aromatic systems.
Used in Pharmaceutical Industry:
2,3,5,6-Tetrafluorobenzoic acid is used as an intermediate in the synthesis of various pharmaceutical compounds. Its fluorinated structure can enhance the properties of the final drug, such as increasing its stability, bioavailability, or targeting specific biological receptors.
Used in Material Science:
In the field of material science, 2,3,5,6-Tetrafluorobenzoic acid is used as a building block for the development of new materials with enhanced properties. Its fluorinated nature can contribute to improved thermal stability, chemical resistance, and other desirable characteristics in the resulting materials.
Used in Chemical Synthesis:
2,3,5,6-Tetrafluorobenzoic acid is used as a starting material or a reagent in the synthesis of various organic compounds. Its unique structure allows for the creation of a diverse range of molecules with potential applications in various industries, such as agrochemicals, dyes, and specialty chemicals.
Used in Analytical Chemistry:
2,3,5,6-Tetrafluorobenzoic acid can be employed as a standard or a reference compound in analytical chemistry. Its well-defined structure and properties make it suitable for calibrating instruments, validating analytical methods, or comparing the performance of different analytical techniques.

InChI:InChI=1/C7H2F4O2/c8-2-1-3(9)6(11)4(5(2)10)7(12)13/h1H,(H,12,13)/p-1

Upstream product

• 602-94-8 Pentafluorobenzoic acid 
• 651-80-9 1,2,4,5-tetrafluoro-3-(trifluoromethyl)benzene 
• 124-38-9 carbon dioxide 
• 355-68-0 perfluorocyclohexane 
• 5211-45-0 4-chloro 2,3,5,6-tetrafluoro benzoic acid 
• 652-36-8 2,3,5,6-tetrafluoroterephthalic acid 
• 109-72-8 n-butyllithium 
• 327-54-8 1,2,4,5-Tetrafluorobenzene 
• 1559-88-2 1-bromo-2,3,5,6-tetrafluorobenzene 
• 5230-78-4 2,3,5,6-tetrafluorotoluene 
• 617-86-7 triethylsilane 
• 944-43-4 4-amino-2,3,5,6-tetrafluorobenzoic acid 
• 127-19-5 N,N-dimethyl acetamide 
• 434-64-0 perfluorotoluene 

Downstream Products

• 53001-73-3 3-(bromomethyl)-1,2,4,5-tetrafluorobenzene 
• 455-38-9 3-fluorobenzoic acid 
• 455-40-3 3,5-difluorobenzoic acid 
• 65-85-0 benzoic acid 
• 107535-73-9 2,3,5,6-tetrafluorobenzoic acid chloride 
• 28442-18-4 4-nitrotetrafluorobenzoic acid 
• 1567382-95-9 2-(2,3,5,6-tetrafluorophenyl)benzo[d]oxazole 
• 837368-26-0 2,3,5,6-tetrafluoro-4-iodo-benzaldehyde 
• 5243-24-3 3-iodo-1,2,4,5-tetrafluorobenzene 
• 34073-32-0 2',3',4',5',6'-Tetrafluor-desoxybenzoin 
• 13664-67-0 2-Pentafluorphenyl-1-p-tolyl-ethanon 

Relevant articles and documents

Optimized synthesis of tetrafluoroterephthalic acid: A versatile linking ligand for the construction of new coordination polymers and metal-organic frameworks

Pure 2,3,5,6-tetrafluoroterephthalic acid (H2tfBDC) is obtained in high yields (95%) by reacting 1,2,4,5-tetrafluorobenzene with a surplus (>2 equiv) of n-butyllithium in tetrahydrofuran (THF) and subsequent carbonation with CO2 without any extensive purification procedure. A single crystal X-ray structure analysis of H2tfBDC (1) confirms former data obtained for a deuterated sample (P1, Z= 1). Recrystallization from water/acetone leads to single crystals of H2tfBDC · 2H2O (2, P21/c, Z= 2), where an extensive hydrogen bonding network is found. By reacting H2tfBDC with an aqueous ammonia solution, single crystals of (NH4)2tfBDC (3, C2/m, Z= 2) are obtained. 3 is thermally stable up to 250 °C and shows an enhanced solubility in water compared to H2tfBDC. Monosubstituted 2,3,5,6-tetrafluorobenzoic acid (H2tfBC, 4) is obtained by reacting 1,2,4,5-tetrafluorobenzene with stoichiometric amounts (1 equiv) of n-butyllithium in THF. Its crystal structure (Fdd2, Z= 16) shows dimeric units as characteristic structural feature.

Lanthanide tetrafluorobenzoates as emitters for OLEDs: New approach for host selection

Brightly luminescent and highly soluble lanthanide tetrafluorobenzoates, as well as their mixed ligand complexes, were synthesized and thoroughly characterized. The low charge carrier mobility hampered their use in OLED, but this problem was overcome by a

Direct evidence of edge-to-face CH/π interaction for PAR-1 thrombin receptor activation

Heptapeptide SFLLRNP is a receptor–tethered ligand of protease-activated receptor 1 (PAR-1), and its Phe at position 2 is essential for the aggregation of human platelets. To validate the structural elements of the Phe-phenyl group in receptor activation, we have synthesized a complete set of S/Phe/LLRNP peptides comprising different series of fluorophenylalanine isomers (Fn)Phe, where n = 1, 2, 3, and 5. Phe-2-phenyl was strongly suggested to be involved in the edge-to-face CH/π interaction with the receptor aromatic group. In the present study, to prove this receptor interaction definitively, we synthesized another series of peptide analogs containing (F4)Phe-isomers, with the phenyl group of each isomer possessing only one hydrogen atom at the ortho, meta, or para position. When the peptides were assayed for their platelet aggregation activity, S/(2,3,4,6-F4)Phe/LLRNP and S/(2,3,4,5-F4)Phe/LLRNP exhibited noticeable activity (34% and 6% intensities of the native peptide, respectively), whereas S/(2,3,5,6-F4)Phe/LLRNP was completely inactive. The results indicated that, at the ortho and meta positions but not at the para position, benzene-hydrogen atoms are required for the CH/π interaction to activate the receptor. The results provided a decisive evidence of the molecular recognition property of Phe, the phenyl benzene-hydrogen atom of which participates directly in the interaction with the receptor aromatic π plane.

Photo-induced deep aerobic oxidation of alkyl aromatics

Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].

Preparation method of 2, 3, 5, 6-tetrafluorobenzoic acid

The invention relates to a preparation method of 2, 3, 5, 6-tetrafluorobenzoic acid and belongs to the field of preparation of fine chemical products. The method comprises that zinc powder and pentafluorobenzoic acid undergo a reaction in aqueous ammonia

Photocyclodehydrofluorination

Mallory-type photocyclization involves a series of photoreactions of stilbenes, o-terphenyls and related derivatives, which undergo intramolecular cyclization via dihydrophenanthrene intermediates. In typical Mallory photocyclizations, oxidants are usually needed to produce the final phenanthrene-containing product. In the research described here, appropriately fluorinated stilbenes and o-terphenyls undergo ring closure and HF is eliminated. This photocyclodehydrofluorination (PCDHF) reaction is very useful to produce a wide range of selectively fluorinated polynuclear aromatic hydrocarbons that possess a phenanthrene (or heterocyclic analogue of phenanthrene) substructure. These fluorinated products are of great interest in various aspects of the materials science.

CARBOXYLATION CATALYSTS

The use of a complex of the form Z—M—OR in the carboxylation of a substrate is described. The group Z is a two-electron donor ligand, M is a metal and OR is selected from the group consisting of OH, alkoxy and aryloxy. The substrate may be carboxylated at a C—H or N—H bond. The metal M may be copper, silver or gold. The two-electron donor ligand may be a phosphine, a carbene or a phosphite ligand. Also described are methods of manufacture of the complexes and methods for preparing isotopically labelled caboxylic acids and carboxylic acid derivatives.

Catalytic C-F bond activation of perfluoroarenes by tricoordinated gold(I) complexes

We report the first example of gold catalyzing C-F bond activation for perfluoroarenes in the presence of silanes. Tricoordinated gold(I) complexes supported by Xantphos-type ligands, such as Xantphos and tBuXantphos ligands, exhibit efficacy in the hydrodefluorination (HDF) of various types of perfluoroarenes. For [tBuXantphosAu(AuCl2)], the highest turnover number is up to 1000 in the HDF of pentafluoronitrobenzene with diphenylsilane. An examination of functional group tolerance shows the orthogonality of this gold(I) catalytic protocol to ketone, ester, carboxylate, alkynyl, alkenyl and amide groups, suggesting its potential application in chemoselective C-F activations. Mechanistic studies show that the equilibrium between tetracoordinated [L2Au]+ and [LAu]+ is important for the reactivity of gold catalysts, which is dependent on the sterically bulky group of Xantphos-type ligands. Furthermore, computational studies for the possible reaction pathways suggest that direct oxidative addition of C-F bonds by gold(I) cation might be the key step during these catalytic reactions. Copyright

Synthesis of tetrafluorinated aromatic amino acids with distinct signatures in 19F NMR

Fluorinated amino acids serve as powerful tools in protein chemistry. We synthesized a series of para-substituted tetrafluorophenylalanines via the regioselective SNAr chemistry of the commercially available pentafluorophenylalanine Boc-Z. Thes

π-π Interaction assisted hydrodefluorination of perfluoroarenes by gold hydride: A case of synergistic effect on C-F bond activation

Synergistic effect is prevalent in natural metalloenzymes in activating small molecules, and the success has inspired the development of artificial catalysts capable of unprecedented organic transformations. In this work, we found that the attractive π-π interaction between organic additives (as electron-donors) and the perfluorinated arenes (as electron acceptors) is effective in gold hydride catalyzed activation of C-F bonds, specifically hydrodefluorination (HDF) of perfluoroarenes catalyzed by the Sadighi's gold hydrides [(NHC)AuH] (NHC = N-heterocyclic carbene). Although a weak interaction between [(NHC)AuH] and perfluoroarenes was observed from 1H NMR and UV-vis spectroscopies, low reactivity of [(NHC)AuH] toward HDF was found. In contrast, in the presence of p-N,N-dimethylaminopyridine (DMAP), the HDF of perfluoroarenes with silanes can be efficiently catalyzed by [(NHC)AuH], resulting in mainly the para-hydrodefluorinated products with up to 90% yield and 9 turnovers. The yield of the reaction increases with the more electron-withdrawing groups and degree of fluorination on the arenes, and the HDF reaction also tolerates different function groups (such as formyl, alkynyl, ketone, ester, and carboxylate groups), without reduction or hydrogenation of these function groups. To reveal the role of DMAP in the reactions, the possible π-π interaction between DMAP and perfluoroarenes was suggested by UV-vis spectral titrations, 1H NMR spectroscopic studies, and DFT calculations. Moreover, 1H and 19F-NMR studies show that this π-π interaction promotes hydrogen transfer from [(NHC)AuH] to pyridyl N atom, resulting in C-F bond cleavage. The interpretation of π-π interaction assisted C-F activation is supported by the reduced activation barriers in the presence of DMAP (31.6 kcal/mol) than that in the absence of DMAP (40.8 kcal/mol) for this reaction. An analysis of the charge distribution and transition state geometries indicate that this HDF process is controlled by the π-π interaction between DMAP and perfluoroarenes, accompanied with the changes of partial atomic charges.