One-pot synthesis, theoretical study and antimicrobial activity of 5,5′-(1,4-phenylenebis-(methanylylidene))Bis(3-Aryl(Alkyl)-2-thioxoimidazolidin-4-one) derivatives

A simple, facile, and convenient practical method for the one-pot synthesis of pharmaceutically interesting 5,5`-(1,4-phenylenebis-(methanylylidene))bis-thiohydantoins via a three-component condensation reaction of terephthalaldehyde, α-amino acids and isothiocyanates had been developed. The S-alkylated derivatives 6a and 6b were obtained by the alkylation of the bis-thiohydantoins 4a with methyl iodide and/or benzyl chloride in a basic media. The molecular structures of the synthesized compounds were confirmed by their elemental analyses and spectral data (IR, 1H, 13C NMR and MS). The assignment of more stable Z- or E-isomers as the major form of 4a, 6a, and 8a was investigated by DFT calculations at B3LYP/6-31+G* level. Some of the prepared compounds were screened for their in-vitro antimicrobial activity. Compounds 4a, 6 b, 8 b and 8c exhibited low antibacterial activity against gram-positive bacteria Bacillus cereus. (5Z,5′Z)-5,5′-(1,4-Phenylenebis(methanylylidene))bis(3-benzyl-2-thioxoimidazolidin-4-one) (4b) exhibited good fungicidal activity against Fusarium oxysporum.