Potassium Hydroxide → 2,5-Bis-(6-hydroxyhexoxy)terephthalic acid

Reaction equation

[OH-].[K+].C([O:5][C:6](=[O:40])[C:7]1[CH:17]=[C:16]([O:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][O:25]C(=O)C)[C:10]([C:11]([O:13]CC)=[O:12])=[CH:9][C:8]=1[O:29][CH2:30][CH2:31][CH2:32][CH2:33][CH2:34][CH2:35][O:36]C(=O)C)C>O.C(O)C>[OH:36][CH2:35][CH2:34][CH2:33][CH2:32][CH2:31][CH2:30][O:29][C:8]1[CH:9]=[C:10]([C:11]([OH:13])=[O:12])[C:16]([O:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][OH:25])=[CH:17][C:7]=1[C:6]([OH:40])=[O:5]

Participants

Procedure

A solution of 25.0 g (379 mmol) 85% KOH in 300 ml water is added to 40.0 g (74.3 mmol) diethyl-2,5-bis-(6-acetoxyhexoxy)terephthalate in 250 ml ethanol and the whole is heated under reflux for 1.5 hours. After distilling off approx. 150 ml ethanol, the reaction mixture is acidified by adding 40.0 g conc. HCl and stored at 2° C. for 20 hours for complete crystallization of the crude product. The colourless crude product is then filtered off, washed neutral with water and recrystallized from ethanol.