A method for the preparation of pure allcis - cyclopentane - 1,2,3,4 - tetracarbonsaeure or. Their salts

摘要

Cis-cyclopentane-1, 2, 3, 4-tetracarboxylic acid is purified by dissolving in aq. alkali, adjusting to pH to 3 to 8.5, then sepg. the pptd. pure salt which pptes., followed by transformation of the pure salt into other salts or into the free acid. The cpd. is used in detergents. Previous process although successfully removing the nitrogen contng. and yellow impurities have caused isomerisation of the cis-form which greatly reduces its complexing power with alkaline earth metals and also the tetra-sodium salt of the isomer form is much more hygroscopic than the cis-form.