LAUSR

Considering benzimidazole as a privileged structure for developing probes of impressive pharmacological potentials, some new coumarin and pyrazole conjugates of benzimidazoles were synthesized with a sulphur linkage. Thus, 3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde (3) was prepared starting from simple salicylaldehyde which has been used as an important synthon and incorporated in a series of structural manipulations to obtain various of pharmacophoric motif conjugates 9(a–b) and 13(a–f), in fair yields. We have developed facile and stepwise methods for the synthesis of all these compounds in various approaches, which also involves sub-sequences. All synthesized compounds were well characterized by IR, 1HNMR, 13CNMR and mass spectra data.Graphical Abstract