7372. Phthalic Anhydride

Nomenclature

CAS number: 85-44-9
1,3-Isobenzofurandione; 1,2-benzenedicarboxylic anhydride.
C8H4O3; mol wt 148.12.
C 64.87%, H 2.72%, O 32.40%.

Description and references

Prepd from naphthalene by oxidation with a mixture of HgSO4 and CuSO4 in presence of H2SO4; by passing naphthalene and oxygen over a suitable catalyst at 400-500°. Review of mfg processes: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds (Wiley-Interscience, New York, 4th ed., 1975) pp 658-665.

Chemical structure

Properties

White, lustrous needles. d 1.53; mp 130.8°; bp 295°. Sublimes. Corrosive. Sol in 162 parts water, more in hot water with conversion into phthalic acid, in 125 parts carbon disulfide; sol in alcohol, sparingly in ether.

Caution

Potential symptoms of overexposure are irritation of eyes, skin and upper respiratory system; conjunctivitis; nasal ulcer bleeding; bronchitis, bronchial asthma; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 256.

Use

Manuf phthaleins, phthalates, benzoic acid, synthetic indigo, artificial resins (glyptal). Buffer.