| 摘要 |
Diaryl esters of aromatic dicarboxylic acids are prepared by directly reacting aromatic dicarboxylic acids with a large molar excess of an aromatic monohydroxy compound, ranging from about 15-17 moles of the aromatic monohydroxy compound which is used as a solvent, reactant and as a carrier to remove water formed during the reaction, the reaction being carried out by heating the reagents at an elevated temperature in the presence of stannous oxide (SnO) as a catalyst at about 275 DEG C. to about 300 DEG C. and removing water formed during the reaction and a major proportion of the aromatic monohydroxy compound from the reaction mixture. The process is especially applicable to the preparation of diaryl esters of isophthalic and terephthalic acid, for example diphenyl isophthalate and diphenyl terephthalate by reacting the acids with an aromatic monohydroxy compound, for example, phenol, giving yields of the diesters of 90-95% plus a 5-10% yield of the corresponding monoaryl ester, or half ester. This mixture can then be reacted with a diaryl carbonate, for example, diphenyl carbonate, to convert the half ester into the diester to give a total yield of diester of about 99.9%.
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