12-12-2022-2027 - Phthalic anhydride & phthalic acid

Phthalic anhydride is the organic compound with the formula C₆H₄(CO)₂O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This white solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the worldwide production volume was estimated to be about 3 million tonnes per year.^[4] 

 

Phthalic anhydride

Names
Preferred IUPAC name 2-Benzofuran-1,3-dione[1]
Other names Isobenzofuran-1,3-dione[1] Phthalic anhydride[1]
Identifiers
CAS Number	85-44-9
3D model (JSmol)	Interactive image
Beilstein Reference	118515
ChEBI	CHEBI:36605
ChEMBL	ChEMBL1371297
ChemSpider	6552
ECHA InfoCard	100.001.461
EC Number	201-607-5
Gmelin Reference	27200
PubChem CID	6811
RTECS number	TI3150000
UNII	UVL263I5BJ
UN number	2214
CompTox Dashboard (EPA)	DTXSID2021159
InChI
SMILES
Properties
Chemical formula	C8H4O3
Molar mass	148.1 g/mol
Appearance	white flakes
Odor	characteristic, acrid[2]
Density	1.53 g/cm3, solid; 1.20 g/mL, molten[2]
Melting point	131.6 °C (268.9 °F; 404.8 K)
Boiling point	295 °C (563 °F; 568 K) sublimates
Solubility in water	0.62 g/100g (20—25 °C); 19.0 g/100g (100 °C); reacts slowly
Vapor pressure	0.0015 mmHg (20 °C)[2]
Magnetic susceptibility (χ)	−67.31×10−6 cm3/mol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H315, H317, H318, H334, H335
Precautionary statements	P261, P264, P270, P271, P272, P280, P285, P301+P312, P302+P352, P304+P340, P304+P341, P305+P351+P338, P310, P312, P321, P330, P332+P313, P333+P313, P342+P311, P362, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 1 0
Flash point	152 °C (306 °F; 425 K)
Explosive limits	1.7%–10.5%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	4020 mg/kg (oral, rat) 1520 mg/kg (oral, mouse) 800 mg/kg (oral, cat) 800–1600 mg/kg (oral, rat) 2210 mg/kg (oral, mouse)[3]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 12 mg/m3 (2 ppm)[2]
REL (Recommended)	TWA 6 mg/m3 (1 ppm)[2]
IDLH (Immediate danger)	60 mg/m3[2]
Related compounds
Related compounds	Phthalic acid Phthalimide Phthalide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).  verify (what is  ?) Infobox references

https://en.wikipedia.org/wiki/Phthalic_anhydride

Phthalic acid is an aromatic dicarboxylic acid, with formula C₆H₄(CO₂H)₂. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale.^[4] Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid. 

 

Phthalic acid

Names
Preferred IUPAC name Benzene-1,2-dicarboxylic acid
Other names 1,2-Benzenedioic acid Phthalic acid Benzene-1,2-dioic acid ortho-Phthalic acid
Identifiers
CAS Number	88-99-3
3D model (JSmol)	Interactive image
ChEBI	CHEBI:29069
ChemSpider	992
ECHA InfoCard	100.001.703
EC Number	201-873-2
PubChem CID	1017
UNII	6O7F7IX66E
CompTox Dashboard (EPA)	DTXSID8021484
InChI
SMILES
Properties
Chemical formula	C8H6O4
Molar mass	166.132 g/mol
Appearance	white solid
Density	1.593 g/cm3, solid
Melting point	207 °C (405 °F; 480 K)[3]
Solubility in water	0.6 g / 100 mL [1]
Acidity (pKa)	2.89, 5.51[2]
Magnetic susceptibility (χ)	-83.61·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)	2 0 0
Related compounds
Related carboxylic acids	Isophthalic acid Terephthalic acid
Related compounds	Phthalic anhydride Phthalimide Phthalhydrazide Phthaloyl chloride Benzene-1,2- dicarboxaldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).  verify (what is  ?) Infobox references

Reactions and uses

Phthalic acid crystals

It is a dibasic acid, with pK_as of 2.89 and 5.51. The monopotassium 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.^[11]

Safety

The toxicity of phthalic acid is moderate with LD₅₀ (mouse) of 550 mg/kg.

Biodegradation

The bacteria Pseudomonas sp. P1 degrades phthalic acid.^[12]

https://en.wikipedia.org/wiki/Phthalic_acid