p-Toluenesulfonic acid → 1,3-Benzenedicarboxylic acid, 5-amino-, dibutyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-1,3-benzenedicarboxylic acid (632 g, 3.49 mol), n-butyl alcohol (7.5 L) and p-toluenesulphonic acid (860 g, 4.52 mol) is loaded into a 10 L reaction vessel and heated to 97° C. under stirring under a reduced pressure of about 450 mBar removing the azeotrope n-butyl alcohol/water that forms. After 11 hours of heating the reaction mixture is concentrated to 2.4 L, cooled to 60° C. and neutralised by the addition of 5M NaOH (0.9 L). The mixture is further cooled to about 10° C. and diluted with water 3.4 L). After 15 hours at room temperature the solid is recovered by filtration, washed with water (2×1 L) and dried yielding the 5-amino-1,3-benzenedicarboxylic acid di-n-butyl ester (930 g, 3.17 mol, yield: 91%).

Provenance & Evidence