The synthesis of phthalate derivatives in high-pressure, high-temperature water

A variety of phthalate derivatives were synthesized effectively in high-temperature, high-pressure water used as either a solvent or a catalyst. This clean method is based on the condensation of o-phthalic acid with an alcohol which is also called esterification. Although it is commonly believed that esters hydrolyze to the corresponding acid and alcohol in the presence of water, in some cases water content as 10% in H2O/ROH mixtures has led to an increase in the formation of dialkyl phthalate esters.After a series of model reactions were conducted, it was found that the conditions preferred, a mixture, 1/9 v/v H2O/ROH and temperature 350 oC were appropriate for obtaining maximum yields. Also moderate to better yields were obtained depending on the nature of the alcohol.