Synthesis and characterization of metal complexes of heterocyclic chalcones

Abstract

Reaction of diethylmalonate with urea and sodium methoxide yielded pyrimidine 2,4, 6-(1H,3H,5H)
trione (A). Pyrimidine 2,4, 6-(1H,3H,5H) trione reacted with acetic anhydride and H2SO4 to form acetyl
linkage with trione (B). Reactions of B with thiophene-2-aldehyde, pyridine-2-aldehyde and pyrrole-2-
aldehyde yielded heterocyclic chalcones namely, 5-methyl-4-thiophene-2-ylmethylene-2,4-dihydropyrazole-3-one (HL1
): (E)-5-(3-(thiophen-2-yl)acryloyl)pyrimidine-2,4,6(1H,3H,5H)-trione (HL2
), (E)-5-
(3-pyridine-2-yl)acryloyl)pyrimidine-2,4,6(1H,3H,5H)-trione (HL3
) and E)-5-(3-(1H-pyrrol2yl)acryloyl)pyrimidine-2,4,6(1H,3H,5H)-trione (HL4
) respectively. HL1
formed complex with Ni(II).
The geometry predicted for this complex is square planer. Ligands HL2
, HL3
and HL4
formed octahedral
complexes with Co(III) and HL3
formed octahedral complex with Fe(III).