摘要

A series of new 5-substituted thiobarbituric acid derivatives 5-acetyl-3-aryl-2-thioxo-dihydropyrimidine-4,6(1H,5H)-diones (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h) were synthesized by one pot cyclocondensation of 1-aroyl-3-arylthioureas with malonic acid in the presence of acetic anhydride. These compounds exist in equilibrium with their enolic tautomeric forms 5-(1-hydroxy ethylidene)-3-aryl-2-thioxo-dihydropyrimidine-4,6-(1H,5H)-diones. The structures were confirmed by spectroscopic data, elemental analyses and in case of the 2d by single crystal X-ray diffraction data. A plausible mechanism for the formation of products is also proposed. Compounds (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h) were evaluated for their preliminary antibacterial activity against a representative panel of Gram positive and Gram negative bacteria using levofloxacin as the reference drug and were found to exhibit promising activity. The tested compounds displayed different levels of inhibitory effects on bacterial strains. Compound 2b showed the maximum efficacy against pathogenic bacteria and was identified as the lead molecule for further structural modifications.

  • 出版日期2014-3