108-67-8 Usage
Chemical Description
Mesitylene and pentamethylbenzene are both steric hindered aromatic compounds, which means they have bulky substituents that affect their reactivity.
Uses
Used in Chemical Synthesis:
Mesitylene is used as a raw material in organic synthesis, particularly for the preparation of trimesic acid, antioxidants, epoxy curing agents, stabilizers for polyester and alkyd resins, and plasticizers. It is also used in the production of dyes such as 2,4,6-trimethylaniline reactive brilliant blue, K-3R, and other dye intermediates.
Used in the Electronics Industry:
Mesitylene acts as a solvent, ligand in organometallic chemistry, and a precursor to 2,4,6-trimethylaniline. It is also used as a developer for photopatternable silicones due to its solvent properties.
Used in Analytical Chemistry:
Mesitylene is used as an internal standard in nuclear magnetic resonance (NMR) samples, taking advantage of the presence of three equivalent protons in its molecular structure.
Used in the Aviation Industry:
Mesitylene is used as an additive and component in aviation gasoline blends, contributing to the performance and efficiency of the fuel.
Used in the Plastics Industry:
Mesitylene is used as an intermediate in the production of anthraquinone vat dyes and UV oxidation stabilizers for plastics, enhancing the durability and stability of plastic materials.
Physical Properties:
Mesitylene is a colorless liquid with a peculiar odor, with an odor threshold concentration of 170 ppbv. It is insoluble in water but soluble in ethanol, benzene, ether, and acetone.
Outline
The molecular structure of mesitylene (also known as mesitylene, molecular formula is C9H12) is σ bond which formed by benzene ring C atoms by means of sp2 hybrid orbital, other C atoms form σ bond by means of sp3 hybrid orbital, it is functional group in the presence of many multi organic compounds. It is aromatic hydrocarbon which obtained by three hydrogens symmetrically-substituted by three methyl in benzene ring.It is widespread in coal tar and certain petroleum. It is colorless liquid, toxic, flammable and explosive. The freezing point is-44.72 ℃, melting point is-44.7 ℃, boiling point is 164.7 ℃, the relative density is 0.8652 (20/4℃). Mesitylene can generate trimesic acid with the oxidation of dilute nitric acid. Pure mesitylene is made by acetone in vapor phase catalytic dehydrationthe at 300~500℃.
Mesitylene is important organic chemical raw material, the use of mesitylene can develop three toluene, trimesic acid, benzoic anhydride and other dye intermediates, it can also be used for the production of antioxidants, polyester resin curing agent, stabilizer, alkyd resins and plasticizers. Since mesitylene is a good solvent, and it is flammable, irritant, and it has low freezing point. In the electronics industry, it is used as developer of photosensitive sheet silicone.
Mesitylene is also common volatile organic compound (VOC) in city, this is mainly generated by the combustion. It plays an important role (including aerosol and tropospheric ozone generation) in many chemical reactions in the atmosphere. Since the three hydrogens on the aromatic ring have the same chemical environment, in the mesitylene magnetic resonance spectrum hydrogen spectrum only has a single peak which peak area is corresponding to three hydrogen in the vicinity of 6.8ppm. Therefore, mesitylene is sometimes used as internal standard substance in proton nuclear magnetic resonance method which comprises aromatic organic samples.
The annual demand of mesitylene is about 100,000 tons in current domestic market.
The above information is edited by the lookchem of Wang Xiaodong.
Production method
1. It is derived by the separation of C9 aromatic hydrocarbon. 2. In the reforming of heavy aromatics the amount of mesitylene is about 11.8%. However, due to its boiling point (164.7 ℃) is extremely close to the boiling point of O-methyl benzene (165.15 ℃), it is difficult to separate for using distillation method. 3.The isomerization method with partial three toluene as raw material can fractionate, and can get mesitylene which the one way yield is 21.6%, the purity is more than 95%, while 4%-7% of by-product is durene, xylene is 9%. The average temperature of reactor bed is 260℃, pressure is 2.35MPa, empty the entire is 1.0h-1, molar ratio of reforming hydrogen and oil is 10: 1, the catalyst is mordenite which lack of aluminum hydrogen form: Cu: Ni: binder = 85.2: 0.5: 15. Under these conditions, the conversion rate of partial three toluene is 46%, selectivity is 47% , one way yield of mesitylene is 21.6%. HF-BF3 is xylene separated and through the method of isomerization by Japanese Mitsubishi Gas Company, by-products contain high concentration of mesitylene of high boiling, the goods can be get by distilled and refined. 4. Acetone in sulfuric acid-catalyzed goes through dehydration synthesis can obtain this goods with the yield of 13%-15%. 4600g (79mol) of industrial acetone is cooled to 0-5℃, and 4160ml concentrated sulfuric acid is added with stirring, the temperature can not exceed 10℃. After addition is completed, cntinue stirring 3-4h, place at room temperature for 18-24h. The product is subjected to steam distillation, mesitylene is separated, then it is washed with alkali, water, and then collect distillation fraction of 210℃, 15g sodium metal is added into this fraction, it is heated to near the boiling point, 2/3 liquid is evaporated. the residue is distilled to 210℃, efficient fractionation collection is done for the 163-167℃ distillate, 430-470g1,3,5-mesitylene can be obtained.
Toxicity grading
Low toxicity.
Acute toxicity
Inhalation-rat LC50: 24000 mg/m/4 hours.
Stimulus data
Skin-Rabbit 20 mg/24 hours of moderate; Eyes-rabbit 500 mg/24 hr mild.
Flammability hazard characteristics
It is inflammable in case of fire, heat, oxidants; when burning stimulated smoke can generate.
Storage characteristics
Treasury should have ventilation and be low-temperature drying; and it should stored separately with oxidants.
Extinguishing agent
Dry powder, dry sand, carbon dioxide, foam, 1211 fire extinguishing agent.
Professional standards
TWA 120 mg/m3; STEL 170 mg/m.
Synthesis Reference(s)
Journal of the American Chemical Society, 92, p. 3232, 1970 DOI: 10.1021/ja00713a078The Journal of Organic Chemistry, 19, p. 923, 1954 DOI: 10.1021/jo01371a008
Air & Water Reactions
Flammable. Insoluble in water.
Reactivity Profile
TRIMETHYLBENZENE is incompatible with the following: Oxidizers, nitric acid .
Hazard
Moderate fire hazard. Toxic by inhalation.
Central nervous system impairment, asthma, and
hematologic effects.
Health Hazard
May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
Fire Hazard
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Safety Profile
Poison by inhalation.
Moderately toxic by intraperitoneal route.
Human systemic effects by inhalation:
sensory changes involving peripheral nerves,
somnolence (general depressed activity), and
structural or functional change in trachea or
bronchi. Reports of leukopenia and
thrombocytopenia in experimental animals.
A mild skin and eye irritant. A flammable
liquid when exposed to heat or flame; can
react vigorously with oxidizing materials.
Violent reaction with HNO3. To fight fire,
use water spray, fog, foam, CO2. Emitted
from modern buildmg materials (CENEAR
69,22,91). When heated to decomposition it
emits acrid smoke and irritating fumes.
Potential Exposure
Mesitylene is used as raw material in
chemical synthesis and as ultraviolet stabilizer; as a paint
thinner, solvent, and motor fuel component; as an intermediate in organic chemical manufacture.
Source
Detected in distilled water-soluble fractions of 87 octane gasoline (0.34 mg/L), 94 octane
gasoline (1.29 mg/L), Gasohol (0.48 mg/L), No. 2 fuel oil (0.08 mg/L), jet fuel A (0.09 mg/L),
diesel fuel (0.03 mg/L), and military jet fuel JP-4 (0.09 mg/L) (Potter, 1996). Schauer et al. (1999)
reported 1,3,5-trimethylbenzene in a diesel-powered medium-duty truck exhaust at an emission
rate of 260 μg/km.
California Phase II reformulated gasoline contained 1,3,5-trimethylbenzene at a concentration of
7.45 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without
catalytic converters were 1.98 and 210 mg/km, respectively (Schauer et al., 2002).
Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from
Gainesville, FL with individual fractions of three individual petroleum products at 24–25 °C for
24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method
602. Average 1,3,5-trimethylbenzene concentrations reported in water-soluble fractions of
unleaded gasoline, kerosene, and diesel fuel were 333, 86, and 13 μg/L, respectively. When the
authors analyzed the aqueous-phase via U.S. EPA approved test method 610, average 1,3,5-
trimethylbenzene concentrations in water-soluble fractions of unleaded gasoline, kerosene, and
diesel fuel were greater, i.e., 441, 91, and 27 μg/L, respectively.
Drinking water standard: No MCLGs or MCLs have been proposed (U.S. EPA, 2000).
Environmental fate
Biological. In anoxic groundwater near Bemidji, MI, 1,3,5-trimethylbenzene anaerobically
biodegraded to the intermediate tentatively identified as 3,5-dimethylbenzoic acid (Cozzarelli et
al., 1990).
Photolytic. Glyoxal, methylglyoxal, and biacetyl were produced from the photooxidation of
1,3,5-trimethylbenzene by OH radicals in air at 25 °C (Tuazon et al., 1986a). The rate constant for
the reaction of 1,3,5-trimethylbenzene and OH radicals at room temperature was 4.72 x 10-11
cm3/molecule?sec (Hansen et al., 1975). A rate constant of 2.97 x 10-8 L/molecule?sec was reported
for the reaction of 1,3,5-trimethylbenzene with OH radicals in the gas phase (Darnall et al., 1976).
Similarly, a room temperature rate constant of 6.05 x 10-11 cm3/molecule?sec was reported for the
vapor-phase reaction of 1,3,5-trimethylbenzene with OH radicals (Atkinson, 1985). At 25 °C, a
rate constant of 3.87 x 10-11 cm3/molecule?sec was reported for the same reaction (Ohta and
Ohyama, 1985).
Chemical/Physical. 1,3,5-Trimethylbenzene will not hydrolyze because it does not contain a
hydrolyzable functional group (Kollig, 1993).
Shipping
UN1993 Flammable liquids, n.o.s., Hazard Class:
3; Labels: 3-Flammable liquid, Technical Name Required.
Purification Methods
Dry it with CaCl2 and distil it from Na in a glass helices-packed column. Treat it with silica gel and redistil it. Alternative purifications include vapour-phase chromatography, or fractional distillation followed by azeotropic distillation with 2-methoxyethanol (which is subsequently washed out with H2O), drying and fractional distilling. More exhaustive purification uses sulfonation by dissolving in two volumes of conc H2SO4, precipitating with four volumes of conc HCl at 0o, washing with conc HCl and recrystallising from CHCl3. The mesitylene sulfonic acid is hydrolysed with boiling 20% HCl and steam distilled. The separated mesitylene is dried (MgSO4 or CaSO4) and distilled. It can also be fractionally crystallised from the melt at low temperatures. [Beilstein 5 IV 1016.]
Incompatibilities
Vapors forms explosive mixture with air.
Violent reaction with nitric acid. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause
fires or explosions. Keep away from alkaline materials,
strong bases, strong acids, oxoacids, epoxides
Waste Disposal
Dissolve or mix the material
with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal,
state, and local environmental regulations must be
observed.
Check Digit Verification of cas no
The CAS Registry Mumber 108-67-8 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,0 and 8 respectively; the second part has 2 digits, 6 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 108-67:
(5*1)+(4*0)+(3*8)+(2*6)+(1*7)=48
48 % 10 = 8
So 108-67-8 is a valid CAS Registry Number.
InChI:InChI=1/C9H12/c1-7-4-8(2)6-9(3)5-7/h4-6H,1-3H3
108-67-8Relevant articles and documents
ON THE REACTIVITY OF V(η-C6H3Me3-1,3,5)2I
Aviles, T.,Teuben, J.H.
, p. 39 - 44 (1983)
V(η-C6H3Me3-1,3,5)2I reacts with reducing agents such as MeLi, Na or Na to yield the neutral complex V(η-C6H3Me3-1,3,5)2 in 70-75percent yield.Reaction of V(η-C6H3Me3-1,3,5)2I with compounds containing suitable donor atoms such as THF,
Pentadienyl, Cyclohexadienyl, and Arene Uranium Borohydride Complexes
Baudry, Denise,Bulot, Emmanuelle,Ephritikhine, Michael
, p. 1369 - 1370 (1988)
The compounds (η-2,4-dimethylpentadienyl)U(BH4)3 (2) and (η-6,6-dimethylcyclohexadienyl)2U(BH4)2 (5) were obtained from the reactions of U(BH4)4 (1) with the corresponding potassium dienyl anions; treatment of (η-2,4-Me2C5H5)3U with TlBH4 gave (η-2,4-Me2C
Direct α-arylation of ketones: The reaction of cyclic ketone enolates with diphenyliodonium triflate
Ryan, John H.,Stang, Peter J.
, p. 5061 - 5064 (1997)
Diphenyliodonium triflate 1a reacts with the lithium enolates of cyclic ketones 2 (ring size = 5 - 8), in the presence of stoichiometric quantities of copper cyanide, to afford the corresponding α-phenylated ketones 3 or α,α'-diphenylated ketones 4.
Catalytic Reduction of Alkyl and Aryl Bromides Using Propan-2-ol
Haibach, Michael C.,Stoltz, Brian M.,Grubbs, Robert H.
, p. 15123 - 15126 (2017)
Milstein's complex, (PNN)RuHCl(CO), catalyzes the efficient reduction of aryl and alkyl halides under relatively mild conditions by using propan-2-ol and a base. Sterically hindered tertiary and neopentyl substrates are reduced efficiently, as well as more functionalized aryl and alkyl bromides. The reduction process is proposed to occur by radical abstraction/hydrodehalogenation steps at ruthenium. Our research represents a safer and more sustainable alternative to typical silane, lithium aluminium hydride, and tin-based conditions for these reductions.
The Triflic Acid-Catalysed Deacylation and Decarboxylation of Polymethylbenzenecarbonyl Derivatives under Mild Conditions
Keumi, Takashi,Morita, Toshio,Ozawa, Yoshihiro,Kitajima, Hidehiko
, p. 599 - 601 (1989)
Sterically hindered acylarenes are deacylated to arenes in good yields on heating in boiling 1,2-dichloroethane containing a catalytic amount of triflic acid and water.Hindered arenecarboxylic acids undergo decarboxylation under the same conditions to give arenes in high yields.
One-Electron Oxidation of Alkylbenzenes in Acetonitrile by Photochemically Produced NO3.: Evidence for an Inner-Sphere Mechanism
Giacco, Tiziana Del,Baciocchi, Enrico,Steenken, Steen
, p. 5451 - 5456 (1993)
The reaction between NO3. and polyalkylbenzenes was studied using 308-nm laser flash photolysis of cerium(IV) ammonium nitrate in the presence of the alkylbenzenes in acetonitrile solution.For all benzenes, with the exception of monoalkylbenzenes and o- and m-xylene, the reaction with NO3. was found to yield the corresponding radical cations and to proceed in an apparently straightforward bimolecular manner.For monoalkylbenzenes and o- and m-xylene, radicals were seen which are derived from the parents by formal loss of H. from the side chain of the aromatic.This reaction proceeds via a complex between the aromatic and NO3. with the decomposition of the complex being rate determining at higher concentrations of aromatic (rate constants for decomposition between 6 * 105 and 4 * 107 s-1).In the complex, electron transfer from the aromatic to NO3. is suggested to be concerted with deprotonation of the incipient radical cation.Formation of a complex between NO3. and aromatics is likely even in those cases where radical cations are observed, with the assumption that in these cases the complex decomposition rate is greater than 6 * 107 s-1.
Accessing Pincer Bis(carbene) Ni(IV) Complexes from Ni(II) via Halogen and Halogen Surrogates
Martinez, Gabriel Espinosa,Ocampo, Cristian,Park, Yun Ji,Fout, Alison R.
, p. 4290 - 4293 (2016)
This communication describes the two-electron oxidation of (DIPPCCC)NiX (DIPPCCC = bis(diisopropylphenyl-benzimidazol-2-ylidene)phenyl); X = Cl or Br) with halogen and halogen surrogates to form (DIPPCCC)NiX3. These complexes represent a rare oxidation state of nickel, as well as an unprecedented reaction pathway to access these species through Br2 and halogen surrogate (benzyltrimethylammonium tribromide). The NiIV complexes have been characterized by a suite of spectroscopic techniques and can readily reduce to the NiII counterpart, allowing for cycling between the NiII/NiIV oxidation states.
Selective and Mild Deacylation of Hindered Acylarenes with Aqueous Trifluoroacetic Acid
Keumi, Takashi,Morita, Toshio,Inui, Yoko,Teshima, Naomi,Kitajima, Hidehiko
, p. 979 - 980 (1985)
Sterically hindered acylarenes are deacylated to arenes in quantitative yields on heating in boiling 85percent trifluoroacetic acid.Hindered arenecarboxylic acids undergo decarboxylation under the same conditions to give arenes in high yields.
Acetone and acetaldehyde oligomerization on TiO2 surfaces
Luo, Shengcheng,Falconer, John L.
, p. 393 - 407 (1999)
Acetone undergoes aldol condensation and cyclization reactions on TiO2 to form mesitylene (1,3,5-trimethylbenzene) below 400 K. The reaction rate is slow on pure anatase TiO2, but on Degussa P25, a mixture of anatase and rutile, more than 20% of a monolayer of acetone forms mesitylene during temperature-programmed desorption or hydrogenation. Other C5-C9 hydrocarbon products also form on both oxidized and reduced TiO2, whereas hexene forms only on reduced TiO2. Acetaldehyde undergoes aldol condensation on both types of TiO2; acetaldehyde either desorbs or forms dimeric condensation products on anatase. However, on Degussa P25 TiO2, trimeric condensation products, higher molecular weight compounds, and coke also form. In addition, C5H8, C5H10, C6H10, and C9H14 form as secondary reaction products of aldol condensation. Surface concentrations of acetaldehyde and acetone are higher on Degussa P25 than on anatase TiO2. Degussa P25 has more sites that catalyze aldolization, and it has more acid sites. These condensation reactions, which take place at relatively low temperature, may be partly responsible for deactivation of Degussa P25 during photocatalytic oxidation.
Reactivity of 17-, 18-, and 19-Electron Cationic Complexes Generated by the Electrochemical Oxidation of Tricarbonyl(mesitylene)tungsten
Zhang, Yun,Gosser,Rieger,Sweigart
, p. 4062 - 4068 (1991)
The electrochemical oxidation of (mesitylene)W(CO)3 (W) in MeCN produces the 17-electron complex W+, which reacts very rapidly with solvent (S) or tri-n-butyl phosphite (P) to give 19-electron species (WS+, WP+) that undergo spontaneous further oxidation to the 18-electron analogues (WS2+, WP2+). The identities of WS2+ and WP2+ were established by voltammetric, IR spectroelectrochemical, and NMR experiments. Although the 17-electron ? 19-electron transformation is not directly observable, digital simulation techniques allowed selection of a probable mechanism and semiquantitative determination of the rate and equilibrium parameters describing the interconversion of the 17-, 18-, and 19-electron species: W+ + S ? WS+, k ? 105 M-1 s-1, Keq ? 10-1 M-1; W+ + P ? WP+, k ? 107 M-1 s-1, Keq ? 3 × 103 M-1 at 298 K. The related 18-electron complex WS2+ is quite reactive, but orders of magnitude less so than W+ and WS+. Experiments with (mesitylene)Cr(CO)3 (Cr) suggest that associative attack by MeCN at the 17-electron Cr+ is 104 times slower than attack at the W+ analogue. This study illustrates the power of digital simulation techniques for interpreting complex mechanistic schemes and characterizing important but unobservable reaction intermediates. Electrochemical oxidation of (arene)W(CO)3 occurs without loss of arene or CO ligands, suggesting that the electroactivation of these complexes may have useful synthetic applications; this contrasts sharply with (arene)Cr(CO)3 analogues, which decompose with loss of arene and CO ligands upon oxidation in MeCN.
