Synthesis and chemical characterization of the novel agronomically relevant pentadentate chelate 2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid (DCHA).
Iron chelates analogous to o,o-EDDHA/Fe(3+) are the fertilizers chosen to treat iron chlorosis in plants growing on calcareous soil. The isomer o,p-EDDHA/Fe(3+) presents less stability but faster assimilation by the plant than o,o-EDDHA/Fe(3+), because only five coordinating groups are able to complex Fe(3+). The new chelating agent 2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid (DCHA) has been synthesized to obtain an iron fertilizer with intermediate stability between o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) and with fast assimilation. Its synthesis has been done starting from phenol, N-acetylethylendiamine, glyoxylic acid, and NaOH in a three-step sequence. The purity of the DCHA chelating agent, its protonation, and Ca(2+), Mg(2+), Fe(3+), and Cu(2+) stability constants, together with its ability to maintain iron in solution in different agronomic conditions, have been determined. The results indicate that the chelate DCHA/Fe(3+) has intermediate stability between those of o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) complexes and that it is capable of maintaining the Fe(3+) in agronomic conditions. This new chelating agent may be effective in correcting iron chlorosis in plants.
López-Rayo
Sandra
S
Departamento de Química Agrícola, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Hernández
Diana
D
Lucena
Juan J
JJ
Escudero
Rosa
R
Gómez-Gallego
Mar
M
Sierra
Miguel A
MA
D001596:Benzylamines / Q000138:chemical synthesis / Q000737:chemistry*; D005308:Fertilizers / Q000032:analysis*; D005998:Glycine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D007502:Iron Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry*; D007536:Isomerism
C552935:2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid; D001596:Benzylamines; D005308:Fertilizers; D007502:Iron Chelating Agents; D005998:Glycine