Synthesis and antimycobacterial activity of 6-arylpurines: the requirements for the N-9 substituent in active antimycobacterial purines.

6-Arylpurines carrying a variety of substituents in the 9-position were prepared by Stille coupling between appropriately substituted 6-chloropurines and aryl(tributyl)tin, and the compounds were screened for antibacterial activity against Mycobacterium tuberculosis H(37)Rv. The lowest minimum inhibitory concentration value, 0.78 microg/mL, was found for 9-benzyl-2-chloro-6-(2-furyl)purine. This compound exhibited relatively low cytotoxicity, and it was active against several singly drug-resistant strains of M. tuberculosis.