Yield:1732-96-3 86%

Reaction Conditions:

at 230 - 260; under 10 - 15 Torr; for 2 h;Inert atmosphere;

Steps:

1

A solution of trimellitic anhydride (1.0 mol)192 g was mixed with ethylene glycol (0.55 mol) of 34 g,Nitrogen emptying. In nitrogen holdContinued protection to a temperature of 230-240 ° C,This time will continue to have water distillate,Close to the theoretical amount of water (18 grams) after the distillation,Vacuum 10-15mmHg down to 260 for 2 hours, cooling,Refined with 900-1200 grams of acetone,The intermediate trimellitic anhydride ethylene glycol ester, white powder 176 grams, the yield of 86%. The intermediate was hydrolyzed with a 5% aqueous solution of sodium hydroxide,Dilute hydrochloric acid to pH = 1-3,Dried to the final product trimellitic acidEthylene glycol esters,White powder 211.8 g, yield 95%.

References:

CN105968050,2016,A Location in patent:Paragraph 0060; 0061