Abstract
A series of some new bisadducts possessing five, six membered and coumarin subunits were synthesized by the condensation of heterocyclic aldehydes with active methylene compounds and characterized by lR, NMR and X-ray crystallographic studies and were assayed as antitubercular agents. Among the bisadducts, 4-hydroxy-3-[(4-hydroxy-2-oxo-2H-3-chromenyl)(3-thienyl)methyl]-2H-2-chromenone 3a was found to be the most promising compound, active against Mycobacterium tuberculosis (Mtb) H(37)Rv and isoniazid resistant Mycobacterium tuberculosis (INHR-Mtb) with minimum inhibitory concentration 5.22 and 8.34 mu M, respectively.