Synthesis of new thiobarbituric acid derived spiroheterobicyclic compounds and their antimicrobial activity.

A series pf novel (7S, 11R)-substituted diphenyl-2,4,8,10-tetraazaspiro [5.5] undecane-3-thio-1,5,9-triones 4a-j and (7S,11R)-substituted diphenyl-2,4,8,10-tetraazaspiro[5.5] undecane-3-thio-1,5 dione, 9-thiones 5a-j were prepared using substituted aldehydes and urea/thiourea in the presence of thiobarbituric acid under solvent free, thermal and microwave conditions catalyzed by ecofriendly K-10 clay. The antibacterial potency of these compounds in vitro on the gram negative strains Escherichia coli and Pseudomonas aeruginosa and gram positive strains Staphyllococcus aureus and Staphylococcus epidermidis was evaluated.