Phthalic acids exercises

Phthalic anhydride is used to make anthraquinone (Exercise 22-19) and to make esters of phthalic acid, which are used widely to plasticize polymers. 

Assume that you could change HPLC columns in this exercise and that you installed a column which contained 3-pm particle size silica. Assume that you used the same mobile-phase composition that you used for the reversed-phase separations that you observed. Explain what you would expect to find if the reversed-phase test mix were injected into this HPLC configuration. Explain why DMP is retained longer (i.e., has the higher k ) than phthalic acid given the same mobile-phase composition. 

Exercise 22-19 Anthraquinone can be synthesized from phthalic anhydride and benzene in two steps. The first step is catalyzed by AICI3, the second by fuming sulfuric acid. Write mechanisms for both reactions and suggest why fuming sulfuric is required in the second step but not in the first. 

Rosin Modifications. This class includes modifications with phenolics, phthalic alkyds, maleic alkyds, and fatty acids and oils. Rosin modifications can be broken out roughly into rosin and rosin esters, unmodified, and rosin and rosin esters, modified. The unmodified classification can be broken down into esters esterified with glycerol and esters esterified with other alcohols. The rosin and rosin esters, modified can then be broken down to those modified with phenolic and other tar acid condensates, those modified with phthalic alkyds, and those modified with maleic or fumaric alkyds. This is a very complicated classification and great care must be exercised in order to keep the classes consistent and comparable over a period of years. 

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