Succinic Acid → Butanedioic acid;butane-1,4-diol

Participants

Reaction Conditions

Reaction Steps

A solution of 590.5 g (5 moles) succinic acid in 602 g (5.1 moles) 1,4-butanediol was introduced at 100° C. into a reaction apparatus made of acid-resistant material with a volume of 5 liters, which was fitted with a high-speed stirrer system of the usual type (turbine agitator; speed of rotation 800 to 1200 rpm) and a distillation column (10 theoretical plates). The mixture was rapidly heated, with stirring, to a reaction temperature of 120 to 130° C. and the water of reaction formed was distilled off at normal pressure. The remainder of the water of reaction was finally removed after a residence time of 1.5 hours at a pressure of 400 mbar and at a reaction temperature of 130 to 160° C. The desired degree of esterification was achieved after a further residence time of 2.0 hours (3.5 hours in total). The oligomeric 1,4-butanediol succinate (1095 g) which was obtained had an average degree of oligoesterification (=number of molecules of succinic acid in the oligoester) of n=4 (as measured by gel permeation chromatography) and an acid number of 58 mg KOH/g reaction mixture.

Provenance & Evidence