It is provided a compound of formula (I')；wherein R5 is selected from the group consisting of -H, -OM, -COOM, -NH2, - SO3M, (C1-C4)alkyl, and halogen； and A is a radical having at least 3 C atoms selected from the group consisting of:i) a radical of formula (i)wherein R7 is selected from the group consisting of -OM, and -COOM, and n is 0, 1 or 2； andii) a radical of formula (ii) or of formula (iii)wherein R8 is selected from the group consisting of -H, (C1-C4)alkyl； and wherein M is independently selected from the group consisting of H, an alkaly metal, and NH4+. It is also provided a process for the preparation thereof, a composition comprising it, and its use for correcting deficiencies of metals in plants.
