- Phthalic acid
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- $48.00 / 5g
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2026-04-21
- CAS:88-99-3
- Min. Order:
- Purity: 99.31%
- Supply Ability: 10g
- Phthalic acid
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- $50.00 / 100kg
-
2026-04-17
- CAS:88-99-3
- Min. Order: 1kg
- Purity: 99%，Electronic grade(Single metal impurity≤ 100ppb) or pharmaceutical grade
- Supply Ability: 100kg
- Phthalic acid
-
- $1.00 / 1KG
-
2026-03-20
- CAS:88-99-3
- Min. Order: 1KG
- Purity: 99%
- Supply Ability: 10 mt
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| | Phthalic acid Basic information |
| | Phthalic acid Chemical Properties |
| Melting point | 210-211 °C (dec.) (lit.) | | Boiling point | 214.32°C (rough estimate) | | bulk density | 960kg/m3 | | density | 1.59 g/cm3 at 15 °C | | vapor pressure | 7.8 hPa (191 °C) | | refractive index | 1.5100 (estimate) | | Fp | 168 °C | | storage temp. | Store below +30°C. | | solubility | methanol: 0.1 g/mL, clear | | pka | 2.89(at 25℃) | | form | Powder | | color | White | | PH | 3.2(1 mM solution);2.55(10 mM solution);2(100 mM solution); | | Water Solubility | 7 g/L (25 ºC) | | Merck | 14,7371 | | BRN | 608199 | | Henry's Law Constant | 4.9×105 mol/(m3Pa) at 25℃, Duchowicz et al. (2020) | | Dielectric constant | 5.1（Ambient） | | Stability: | Stable. Combustible. Incompatible with strong oxidizing agents. | | InChI | 1S/C8H6O4/c9-7(10)5-3-1-2-4-6(5)8(11)12/h1-4H,(H,9,10)(H,11,12) | | InChIKey | XNGIFLGASWRNHJ-UHFFFAOYSA-N | | SMILES | OC(C1=C(C(O)=O)C=CC=C1)=O | | LogP | 0.73 at 20℃ | | CAS DataBase Reference | 88-99-3(CAS DataBase Reference) | | NIST Chemistry Reference | 1,2-Benzenedicarboxylic acid(88-99-3) | | EPA Substance Registry System | Phthalic acid (88-99-3) |
| Hazard Codes | Xi | | Risk Statements | 36/37/38 | | Safety Statements | 26-36-37/39 | | WGK Germany | 1 | | RTECS | TH9625000 | | TSCA | TSCA listed | | HS Code | 29173980 | | Storage Class | 11 - Combustible Solids | | Hazard Classifications | Eye Dam. 1 | | Hazardous Substances Data | 88-99-3(Hazardous Substances Data) | | Toxicity | LD50 orally in rats: 7.9 g/kg (Shaffer) |
| | Phthalic acid Usage And Synthesis |
| Description | Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2. It is an isomer of isophthalic acid and terephthalic acid. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale. | | Chemical Properties | PHTHALIC ACID,C6H4(COOH)2, mp 208 °C (ortho), 330 °C (meta and iso), the ortho form sublimes and the meta and iso forms decompose with heat, sp gr 1.593 (ortho). Phthalic acid is very slightly soluble in H2O, soluble in alcohol, and slightly soluble in ether. The solid form is colorless, crystalline | | Uses | It is a dibasic acid, with pKa's of 2.89 and 5.51. The mono potassium salt, potassium hydrogen phthalate is a standard acid in analytical chemistry. Typically phthalate esters are prepared from the widely available phthalic anhydride. Reduction of phthalic acid with sodium amalgam in the presence of water gives the 1,3- cyclohexadiene derivative. | | Uses | Phthalic Acid (Phenyl-13C6, D4) is labelled Phthalic Acid (P384480) which is an organic reagent used to synthesize phthalates. | | Definition | ChEBI: Phthalic acid is a benzenedicarboxylic acid cosisting of two carboxy groups at ortho positions. It has a role as a human xenobiotic metabolite. It is a conjugate acid of a phthalate(1-). | | Production Methods | Phthalic acid is produced by the catalytic oxidation of naphthalene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride.
Phthalic acid was first obtained by French chemist Auguste Laurent in 1836 by oxidizing naphthalene tetrachloride. Believing the resulting substance to be a naphthalene derivative, he named it "naphthalic acid". After the Swiss chemist Jean Charles Galissard de Marignac determined its correct formula, Laurent gave it its present name. Manufacturing methods in the nineteenth century included oxidation of naphthalene tetrachloride with nitric acid, or, better, oxidation of the hydrocarbon with fuming sulfuric acid, using mercury or mercury(II) sulfate as a catalyst. | | Definition | phthalic acid: colourlesscrystalline dicarboxylic acid,C6H4(COOH)2; r.d. 1.6; m.p. 207°C.The two –COOH groups are substitutedon adjacent carbon atoms ofthe ring, the technical name beingbenzene-1,2-dicarboxylic acid. Theacid is made from phthalic anhydride(benzene-1,2-dicarboxylic anhydride,C8H4O3), which is made by the catalyticoxidation of naphthalene. Theanhydride is used in making plasticizersand polyester resins. | | Synthesis Reference(s) | The Journal of Organic Chemistry, 30, p. 2414, 1965 DOI: 10.1021/jo01018a074 | | General Description | White crystals or fine white powder. | | Air & Water Reactions | Insoluble in water. | | Reactivity Profile | Phthalic acid is a carboxylic acid. Phthalic acid is sensitive to exposure to extreme heat. Phthalic acid reacts violently with nitric acid. Phthalic acid is incompatible with sodium nitrite. Phthalic acid is also incompatible with oxidizers. . | | Fire Hazard | Phthalic acid is combustible. | | Flammability and Explosibility | Not classified | | Safety Profile | Moderately toxic by
ingestion and intraperitoneal routes. A skin
and mucous membrane irritant.
Combustible when heated. In the form of
dust (anhydride) it can explode. Mixtures
with sodmm nitrite explode when heated.
Violent reaction with HNO3. When heated
to decomposition it emits acrid smoke and
irritating fumes. Used in synthesis of dyes
and dyestuffs, in medcines and perfumes. | | Safety | The toxicity of phthalic acid is low with LD50 (mouse) of 550 mg/kg. However, many phthalate esters have been implicated as endocrine disruptors. | | Synthesis | Add 97.2 kg of water to the reactor, add an equal mass of 65% concentrated nitric acid under stirring, and heat to 95℃ for reflux to prepare a nitric acid solution; dissolve 48.6 kg of phthalhydrazide in 280 kg of water, slowly add the solution dropwise to the nitric acid solution at 90–110℃ over 2–3 hours, feed the generated reaction gas into a spray absorption tower, reflux for 1 hour after the completion of dropwise addition, continue refluxing for another 35 minutes after the reaction solution becomes clear, then cool to 5–10℃ and filter; wash the solid with 50 kg of water, drain the water, and dry at 80℃ to obtain 45.8 kg of crude phthalic acid; add the crude product to 350 kg of water, heat to 90–105℃ for reflux for 50–60 minutes until complete dissolution, cool to 5–10℃ for crystallization for 2 hours, filter, wash the solid with 50 kg of water, drain the water, and dry at 80℃ to obtain 43.1 kg of refined phthalic acid product. | | Purification Methods | Crystallise phthalic acid from water. [Beilstein 9 IV 3167.] | | Isomers | Phthalic acid is one of three isomers of benzene dicarboxylic acid, the others being iso phthalic acid and terephthalic acid. Sometimes the term "phthalic acids" is used to refer to this family of isomers, but in the singular, "phthalic acid", refers exclusively to the ortho- isomer. |
| | Phthalic acid Preparation Products And Raw materials |
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