Synthesis and Production
Phthalic anhydride was first reported in 1836 by Auguste Laurent. It is presently obtained by catalytic oxidation of ortho-xylene and naphthalene ("Gibbs phthalic anhydride process"):
- C6H4(CH3)2 + 3 O2 → C6H4(CO)2O + 3 H2O
- C10H8 + 4.5 O2 → C6H4(CO)2O + 2 H2O + 2 CO2
The catalyst that is used for the oxidation of xylene is a modified vanadium pentoxide (V2O5). When separating the phthalic anhydride from byproducts such as o-xylene in water, or maleic anhydride, a series of “switch condensers” is required. Phthalic anhydride can also be prepared from phthalic acid:
Read more about this topic: Phthalic Anhydride
Famous quotes containing the words synthesis and/or production:
“The new shopping malls make possible the synthesis of all consumer activities, not least of which are shopping, flirting with objects, idle wandering, and all the permutations of these.”
—Jean Baudrillard (b. 1929)
“The production of obscurity in Paris compares to the production of motor cars in Detroit in the great period of American industry.”
—Ernest Gellner (b. 1925)