Synthesis and biological evaluation of some 4-(6-substituted-1,3-benzothiazol-2-yl)amino-1,3-thiazole-2-amines and their Schiff bases

With the aim of obtaining newer biologically active compounds, a series of 4-(6-substituted-1,3-benzothiazol-2-yl)amino-1,3-thiazole-2-amines (9–12) and 4-(6-substituted-1,3-benzothiazol-2-yl)amino-2-(4-substitutedphenyl-methylidene)amino-1,3-thiazole (13–28) were synthesized. The structures of all the synthesized compounds were confirmed by spectral (FTIR, 1H NMR and EI-MS) data and elemental (C, H, N) analysis. Furthermore, compounds (9–12) and (13–28) were screened for antibacterial, antifungal and anthelmintic activities. Almost all of these compounds showed moderate to excellent antimicrobial activity against two gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa), two gram positive bacteria (Staphylococcus aureus, Bacillus subtilis), pathogenic fungal strains (Candida albicans, Aspergillus niger) and good anthelmintic activity against earthworm species (Pontoscotex corethruses). Among the compounds tested, compounds 23 and 24 showed maximum activity against Gram negative and Gram positive bacteria, respectively. Compound 22 exhibited good antifungal activity while compound 26 displayed maximum anthelmintic activity comparable to the standard drugs.