SYNTHESIS AND BIOLOGICAL SCREENING OF PYRIMIDINE LINKED BENZENE SULPHONAMIDE DERIVATIVES

Background: It has been developed a new combination of Palladium catalyzed Buchwald-Hartwig type reaction for the synthesis of N–tert– Butyl- 3- {[5- methyl- 2- (arylamino)pyrimidin- 4- yl]amino}benzene-sulfonamides 5 by the treatment of N–tert-butyl-3-[(2-chloro-5-methyl pyrimidin-4-yl)-amino]benzene sulfonamide 4 with various aromatic amines in the presence of Cs₂CO₃ and in DMF under microwave conditions. Method: All the eight compounds 5a-h were screened in-vitro for their antibacterial Gram-positive bacteria namely, Bacillus subtilis, Bacillus sphaericus and Staphylococcus aureus and three Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella aerogenes, Chromobacterium violaceum. All the synthesized compounds were tested for their antifungal activity against five test organisms, Aspergillus niger, Chrysosporium tropicum, Rhizopus oryzae, Fusarium moniliforme and Curvularia lunata. Results: Among the title compounds 5d and 5e exhibited potent activity towards both gram positive and gram negative bacteria. Compounds 5e and 5f showed good antifungal activity. Conclusion: A new efficient catalyst/ligand combination was developed for the synthesis of title compounds 5a-5h under microwave conditions. The microwave procedure is slightly superior to the conventional method in terms of reduced time period and better yields.