528-44-9

Basic information

• Product Name: Trimellitic acid
• Synonyms: 1,2,4-Tricarboxybenzene;1,3,4-Benzenetricarboxylic acid;1,4,5-Benzenetricarboxylic acid;4-Carboxyphthalic acid;F-TMA;NSC 72986;Trimellitic acid;1,2,4-Benzenetricarboxylic acid
• CAS NO: 528-44-9
• Molecular Formula: C₉H₆O₆
• Molecular Weight: 210.14034
• EINECS: 208-432-3
• Mol File: 528-44-9.mol
• Article Data: 57

Chemical Properties

• Melting Point: 229-231℃
• Boiling Point: 505.51 °C at 760 mmHg
• Flash Point: 273.614 °C
• Appearance: white crystalline powder
• Density: 1.654 g/cm³
• Vapor Pressure: 4.85E-11mmHg at 25°C
• Water Solubility: 2.1 g/100 mL (25℃)
• CAS DataBase Reference: Trimellitic acid(CAS DataBase Reference)
• NIST Chemistry Reference: Trimellitic acid(528-44-9)
• EPA Substance Registry System: Trimellitic acid(528-44-9)

Safety Data

• Hazard Codes: Xi:Irritant
• Statements: R36/37/38:
• Safety Statements: S26:; S37/39:
• Hazardous Substances Data: 528-44-9(Hazardous Substances Data)

Usage

General Description

Trimellitic acid is a tricarboxylic acid with the chemical formula C9H6O6. It is a white crystalline solid that is used in the production of various polymers, including polyester resins and polyamides. Trimellitic acid is also used as a corrosion inhibitor, a plasticizer, and as a precursor for the production of pharmaceuticals and dyes. It is soluble in water and has a melting point of 164-166°C. The acid is an irritant to the skin, eyes, and respiratory system, and should be handled with care in a well-ventilated area.

InChI:InChI=1/C9H6O6/c10-7(11)4-1-2-5(8(12)13)6(3-4)9(14)15/h1-3H,(H,10,11)(H,12,13)(H,14,15)/p-3

Synthetic route

2.6-dimethylnaphthalene (581-42-0) → 2,6-Naphthalenedicarboxylic acid (1141-38-4) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With oxygen; complex catalyst comprising 6.21 wtpercent Co, 1.58 wtpercent Mn, 3.87 wtpercent Br In water; acetic acid at 200℃; under 14711.4 Torr; Product distribution / selectivity;	A 99.41% B n/a
With oxygen; complex catalyst comprising 5.0 wtpercent Co, 1.0 wtpercent Mn, 3.87 wtpercent Br In water; acetic acid at 200℃; under 14711.4 Torr; Product distribution / selectivity;	A 99.02% B n/a

1,2,4-Trimethylbenzene (95-63-6) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With air; acetic acid; 1N,3N,5N-trihydroxy-1,3,5-triazin-2,4,6[1H,3H,5H]-trione; cobalt(II) acetate; zirconyl acetate at 150℃; under 15200 Torr; for 6h;	97%
With 7H2O*3H3N*3H(1+)*[FeMo6O18(OH)6](3-); sodium carbonate; acetic acid at 100℃; under 750.075 Torr; for 12h; Reagent/catalyst; Temperature; Inert atmosphere;	97%
With cobalt(II) acetate; manganese(II) acetate; acetic acid at 110 - 220℃; under 14251.4 - 16501.7 Torr; Pressure; Temperature;	96.32%

2-cyano-1,4-benzenedicarboxylic acid → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With water; sodium hydroxide at 115℃; for 5h;	96%
With potassium hydroxide

3,4-dimethylbenzoic acid (619-04-5) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Stage #1: 3,4-dimethylbenzoic acid With ferric(III) bromide; manganese(II) bromide tetrahydrate; water; hydrogen bromide; oxygen at 220℃; under 7500.75 - 24002.4 Torr; Inert atmosphere; Stage #2: With bromine In water under 21752.2 Torr;	93%
With N-hydroxyphthalimide; oxygen; cobalt(II) acetate; manganese (II) acetate tetrahydrate In acetic acid at 120℃; under 760.051 Torr; for 14h;	90%

2,4-dimethyl-benzoic acid (611-01-8) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Stage #1: 2,4-dimethyl-benzoic acid With air at 220℃; under 24002.4 Torr; Stage #2: With air at 220℃; under 21752.2 Torr;	92.3%
With nitric acid

2,4-dimethylbenzaldehyde (15764-16-6) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Stage #1: 2,4-dimethylbenzaldehyde With air at 220℃; under 24002.4 Torr; Stage #2: With air at 220℃; under 21752.2 Torr;	92%
Stage #1: 2,4-dimethylbenzaldehyde With air at 220℃; under 24002.4 Torr; Stage #2: With air at 220℃; under 21752.2 Torr;	92.1%
Stage #1: 2,4-dimethylbenzaldehyde With air at 220℃; under 24002.4 Torr; Stage #2: With air at 220℃; under 21752.2 Torr;	92.2%

3,4-dimethylbenzaldehyde (5973-71-7) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Stage #1: 3,4-dimethylbenzaldehyde With ferric(III) bromide; manganese(II) bromide tetrahydrate; water; hydrogen bromide; oxygen at 220℃; under 7500.75 - 24002.4 Torr; Inert atmosphere; Stage #2: With bromine In water under 21752.2 Torr; Product distribution / selectivity;	92%

benzene-1,2,4-tricarboxylic acid trimethyl ester (2459-10-1) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With water; sodium hydroxide In methanol at 70℃; for 48h; Temperature;	90.16%

1,2,4-Trimethylbenzene (95-63-6) → isophthalic acid (121-91-5) + terephthalic acid (100-21-0) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With oxygen; titanium(IV) isopropylate; tetrabutoxytitanium; manganese(II) acetate; cobalt(II) acetate; ammonium bromide; cerous nitrate In water; acetic acid at 150 - 225℃; under 5250.53 - 18751.9 Torr; for 1.2 - 1.25h; Product distribution / selectivity;	A n/a B n/a C 88.3%

2,6-diisopropylnaphthalene (24157-81-1) → 2,6-Naphthalenedicarboxylic acid (1141-38-4) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With manganese; hydrogen bromide; potassium acetate; cobalt; acetic acid at 169.84℃; under 15001.5 Torr; Concentration; Temperature; Reagent/catalyst; Inert atmosphere;	A 75.7% B 15.5%

1,2,4-Trimethylbenzene (95-63-6) + 2,4-dimethyl-benzoic acid (611-01-8) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Stage #1: 1,2,4-Trimethylbenzene; 2,4-dimethyl-benzoic acid With oxygen; cobalt(II) acetate In water at 120℃; under 3000.3 Torr; for 0.833333h; Stage #2: copper naphthenate; cobalt naphthenate at 170℃; under 3000.3 Torr; for 2h; Stage #3: With oxygen; manganese(II) bromide; hydrogen bromide at 220℃; under 24752.5 Torr; for 1.5h; Conversion of starting material;	66.6%
Stage #1: 1,2,4-Trimethylbenzene; 2,4-dimethyl-benzoic acid With oxygen; cobalt(II) acetate In water at 120℃; under 3000.3 Torr; for 0.833333h; Stage #2: copper naphthenate; magnesium naphthenate at 170℃; under 3000.3 Torr; for 2h; Stage #3: With oxygen; manganese(II) bromide; hydrogen bromide at 220℃; under 24752.5 Torr; for 1.5h; Conversion of starting material;	48.6%

1,2,4-Trimethylbenzene (95-63-6) → isophthalic acid (121-91-5) + terephthalic acid (100-21-0) + 1,2,4-benzene tricarboxylic acid (528-44-9) + benzene-1,2-dicarboxylic acid (88-99-3)

Conditions	Yield
With sodium hydroxide; water; dihydrogen peroxide; manganese(II) bromide at 380℃; under 172517 Torr;	A n/a B n/a C 50% D n/a

methyl coumalate (6018-41-3) + acetylenedicarboxylic acid diethyl ester (762-21-0) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
at 155℃; Destillieren des Reaktionsprodukts im Vakuum und Verseifen mit methylalkoh.KOH;
at 155℃; Erwaermen des Reaktionsprodukts mit methanol. Kalilauge;

1,2,4-triisopropylbenzene (948-32-3) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With nitric acid

2-methylterephthalic acid (5156-01-4) → isophthalic acid (121-91-5) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With alkaline potassium permanganate

2-methylterephthalic acid (5156-01-4) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With potassium permanganate

4-sulfophthalic acid (89-08-7) + sodium formate (141-53-7) → isophthalic acid (121-91-5) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
Reaktion des Kaliumsalzes, Schmelzen;

2,5-dimethylbenzyl chloride (824-45-3) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With potassium permanganate

1,2,3,4-tetrahydro-2-naphthoic acid (1131-63-1) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With potassium permanganate
With nitric acid at 140℃; im Rohr;

2,6-dimethyl-1,4-naphthoquinone (6290-94-4) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With potassium permanganate; water

indan-5-carboxylic acid (65898-38-6) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With alkaline permanganate
With nitric acid at 140℃; im Rohr;

4-(tert-butyl)-2-methylbenzoic acid (33691-85-9) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With nitric acid at 240℃;

4-cyano-phthalic acid diethyl ester (105903-40-0) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With sodium hydroxide

3-(2-ethyl-butyryl)-[2]naphthoic acid → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With nitric acid at 120 - 140℃; im Rohr;

2,4-bis-trichloromethyl-benzoyl chloride (622367-70-8) → 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With water; calcium carbonate

biphenyl-2,4,3'-tricarboxylic acid → isophthalic acid (121-91-5) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
bei der Oxydation;

4,4'-carbonyl-di-isophthalic acid (101439-06-9) → isophthalic acid (121-91-5) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
at 280 - 285℃; bei der Kalischmelze;

propargyl alcohol (107-19-7) → benzene-1,3,5-tricarboxylic acid (554-95-0) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With bis(triphenylphosphine)nickel(0) dicarbonyl; benzene Erwaermen des Reaktionsprodukts mit wss. Salpetersaeure;

ethylbenzene (100-41-4) + 1,2-dichloro-ethane (107-06-2) → benzene-1,3,5-tricarboxylic acid (554-95-0) + 1,2,4-benzene tricarboxylic acid (528-44-9)

Conditions	Yield
With aluminium trichloride Erhitzen des Reaktionsprodukts mit HNO3 auf 180grad;
With aluminium trichloride Erwaermen des Reaktionsprodukts mit HNO3 auf 180grad;

methanol (67-56-1) + 1,2,4-benzene tricarboxylic acid (528-44-9) → benzene-1,2,4-tricarboxylic acid trimethyl ester (2459-10-1)

Conditions	Yield
With boron trifluoride at 65℃; for 0.333333h;	100%
With sulfuric acid
With hydrogenchloride
With sulfuric acid

1,2,4-benzene tricarboxylic acid (528-44-9) → ammonium trimellitate (7572-36-3, 78759-00-9, 123368-95-6, 123368-96-7)

Conditions	Yield
With ammonia In water for 1.5h; Heating;	99.7%

zirconyl(IV) nitrate hydrate + 1,2,4-benzene tricarboxylic acid (528-44-9) + benzoic acid (65-85-0) → [Zr6O4(OH)4(1,4-benzenedicarboxylate-CO2H)6]·2.0(1,4-benzenedicarboxylic acid-CO2H)

Conditions	Yield
In N,N-dimethyl-formamide at 150℃; for 24h;	95%

1,2,4-benzene tricarboxylic acid (528-44-9) + water (7732-18-5) + zinc(II) acetate dihydrate (5970-45-6) + N,N’-di(3-pyridyl)adipoamide (39642-63-2) → [Zn3(1,2,4-benzenetricarboxylate)2(N,N′-di(3-pyridyl)adipoamide)(H2O)4]·4H2O

Conditions	Yield
at 120℃; for 48h; Autoclave; High pressure;	95%

2-Ethylhexyl alcohol (104-76-7) + 1,2,4-benzene tricarboxylic acid (528-44-9) → Hatcol 200 (3319-31-1)

Conditions	Yield
With triflic acid on silica-encapsulated superparamagnetic iron oxide nanoparticles In neat (no solvent) at 90℃; for 0.416667h; Catalytic behavior; Time; Reagent/catalyst; Flow reactor; Green chemistry;	95%

1,2,4-benzene tricarboxylic acid (528-44-9) + butan-1-ol (71-36-3) → tris(n-butyl) trimellitate (1726-23-4)

Conditions	Yield
With triflic acid on silica-encapsulated superparamagnetic iron oxide nanoparticles In neat (no solvent) at 90℃; for 1.33333h; Catalytic behavior; Time; Reagent/catalyst; Flow reactor; Green chemistry;	92%
With microporous aluminosilicates zeolite HBeta In toluene at 117℃; for 5h; Dean-Stark;

1,2,4-benzene tricarboxylic acid (528-44-9) → [Li11(H3O)(H2O)5(1,2,4-benzenetricarboxylic acid(-2H))6]

Conditions	Yield
With 1,4-dioxane; water In methanol; water at 80℃; for 24h;	90%

1,2,4-benzene tricarboxylic acid (528-44-9) + 4′-(4-carboxyphenyl)-3,2′:6′,3″-terpyridine (1415258-35-3) + zinc(II) acetate dihydrate (5970-45-6) → [Zn2(4′-(4-carboxyphenyl)-3,2′:6′,3″-terpyridine(-1H))(1,2,4-benzenetricarboxylic acid(-3H))]n

Conditions	Yield
With sodium hydroxide In water at 180℃; for 72h; pH=5; Sealed tube;	89%

2,4,6-triamino-s-triazine (108-78-1) + 1,2,4-benzene tricarboxylic acid (528-44-9) → C9H6O6*C3H6N6

Conditions	Yield
In water at 120℃; for 2h; Autoclave;	85%

[2,2]bipyridinyl (366-18-7) + 1,2,4-benzene tricarboxylic acid (528-44-9) + water (7732-18-5) + cobalt(II) diacetate tetrahydrate (6147-53-1) → Co3(C5H4N)4(C6H3(COO)3)2(H2O)2 (347412-36-6)

Conditions	Yield
In water High Pressure; heated at a rate of 20°C/h to 230°C; maintaining at this temp. for 2 h; cooling at a rate of 5°C/h to 180°C; cooled at 2°C/h to 90°C; cooled to 50°C at 4°C/h; cooled to room temp. (5°C/h); elem.anal.;	81%

[2,2]bipyridinyl (366-18-7) + 1,2,4-benzene tricarboxylic acid (528-44-9) + water (7732-18-5) + manganese (II) acetate tetrahydrate (6156-78-1) → Mn3(C5H4N)4(C6H3(COO)3)2(H2O)2 (347412-37-7)

Conditions	Yield
In water High Pressure; heated at a rate of 20°C/h to 230°C; maintaining at this temp. for 2 h; cooling at a rate of 5°C/h to 180°C; cooled at 2°C/h to 90°C; cooled to 50°C at 4°C/h; cooled to room temp. (5°C/h); elem.anal.;	80%

pyridin-4-ol (626-64-2) + 1,2,4-benzene tricarboxylic acid (528-44-9) → 2C5H5NO*C9H6O6

Conditions	Yield
In dimethyl sulfoxide at 90℃;	80%

1,2,4-benzene tricarboxylic acid (528-44-9) → trimellitic acid amide-imide (21343-93-1)

Conditions	Yield
With urea at 250℃; for 2h;	80%

indium(III) nitrate pentahydrate + 1,2,4-benzene tricarboxylic acid (528-44-9) → [H3O][In2(1,2,4-benzenetricarboxylate)(1,4-benzenedicarboxylate)(OH)2]*5.5H2O

Conditions	Yield
With piperazine In water High Pressure; mixt. of In(NO3)3*5H2O, 1,2,4-benzenetricarboxylic acid, piperazine, H2Oplaced in autoclave, heated at 443 K for 3 d, cooled to room temp. at 1 0 K/h; washed with H2O, dried in air; elem. anal.;	78%

cadmium(II) nitrate tetrhydrate + 1,2,4-benzene tricarboxylic acid (528-44-9) + 3,2′:6′,3′′-terpyridine-4′-carboxylic acid (1214357-77-3) → [Cd4(3,2′:6′,3′′-terpyridine-4′-carboxylate)2(1,2,4-benzenetricarboxylate)2(H2O)2]*2H2O

Conditions	Yield
With sodium hydroxide In water at 180℃; for 72h; pH=5; High pressure; Autoclave;	77%

bismuth (III) nitrate pentahydrate + 1,2,4-benzene tricarboxylic acid (528-44-9) + water (7732-18-5) → Bi(Tri)(H2O)

Conditions	Yield
With nitric acid In water at 150℃; for 12h;	76.6%

1,2,4-benzene tricarboxylic acid (528-44-9) + diphenyl acetylene (501-65-5) → 5,6,7,8-tetraphenyl-1,3-naphthalenedicarboxylic acid

Conditions	Yield
With [ruthenium(II)(η6-1-methyl-4-isopropyl-benzene)(chloride)(μ-chloride)]2; tetrabutylammomium bromide; 5-methyl-dihydro-furan-2-one In N,N-dimethyl-formamide at 100℃; for 12h;	76%
With [ruthenium(II)(η6-1-methyl-4-isopropyl-benzene)(chloride)(μ-chloride)]2; tetrabutylammomium bromide In N,N-dimethyl-formamide at 100℃; for 12h; Sealed tube;	76%

1,2,4-benzene tricarboxylic acid (528-44-9) + urea (57-13-6) + cobalt(II) chloride (7646-79-9) → (29H,31H-2,9,16,23-tetracarboxyphthalocyaninato-N(29),N(30),N(31),N(32))cobalt(II) (69934-86-7)

Conditions	Yield
With sodium sulfate; ammonium molybdate In further solvent(s) a mixt. in 1-bromonaphthalene was stirred for 4 h at 210-215°C, cooled; diluted with methanol, filtered, washed with methanol, CHCl3 and water, squeezed, dried, refluxed with 10 NaOH (6 h) and 10 HCl (1 h); elem. anal.;	75%

zinc(II) sulfate heptahydrate + 1,2,4-benzene tricarboxylic acid (528-44-9) + 1-(1H-imidazol-4-yl)-4-(4H-tetrazol-5-yl)benzene → [Zn3((1H-imidazol-4-yl)-4-(4H-tetrazol-5-yl-1-ido)benzene)3(1,2,4-benzenetricarboxylato)]

Conditions	Yield
In water; N,N-dimethyl-formamide at 180℃; for 72h; Autoclave;	75%

Upstream product

• 6018-41-3 methyl coumalate 
• 762-21-0 acetylenedicarboxylic acid diethyl ester 
• 948-32-3 1,2,4-triisopropylbenzene 
• 5156-01-4 2-methylterephthalic acid 
• 1131-63-1 1,2,3,4-tetrahydro-2-naphthoic acid 
• 107-19-7 propargyl alcohol 
• 89-20-3 4-chlorophthalic acid 
• 201230-82-2 carbon monoxide 
• 56962-08-4 4,5-dichlorophthalic acid 
• 93-09-4 naphthalene-2-carboxylate 
• 4593-38-8 5-methylindan-1-one 
• 7697-37-2 nitric acid 
• 95-63-6 1,2,4-Trimethylbenzene 
• 64-19-7 acetic acid 

Downstream Products

• 14230-18-3 triethyl benzene-1,2,4-tricarboxylate 
• 92-52-4 biphenyl 
• 71-43-2 benzene 
• 25147-76-6 [2,4-bis(hydroxymethyl)-phenyl]methanol 
• 64884-25-9 1,2,4-Tris(mercaptomethyl)benzol 
• 61124-37-6 1,2,4-tris(bromomethyl)benzene 
• 69934-86-7 (29H,31H-2,9,16,23-tetracarboxyphthalocyaninato-N⁽²⁹⁾,N⁽³⁰⁾,N⁽³¹⁾,N⁽³²⁾)cobalt(II) 

Relevant articles and documents

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