Ethylenediamine-N,N'-bis((2-hydroxyphenyl)acetic acid)

EDDHA is used as an inorganic fertilizer.

EDDHA is short for Ethylenediamine-N,N'-bis((2-hydroxyphenyl)acetic acid. It is a chelating agent (C₁₈H₂₀O₆N₂) that forms a chelate, which complexes with metal ions. Fe-EDDHA, which is stable over an entire pH range, is commonly used as an iron fertilizer because of its affinity to iron. The comparison of a soil treated with iron chelates, such as EDTA (ethylenediamine tetra- aceticacid), DTPA (diethylenetriaminepentaaceticacid) or EDDHA shows that EDDHA is most effective in making iron available to plants.

Purify it by extensive Soxhlet extraction with acetone. [Bonadies & pK Est( 2) pK Est( 3) Carrano J Am Chem Soc 108 4088 1986].