Convenient syntheses of 6-methylpurine and related nucleosides

Efficient methods for the synthesis of 6-methylpurine (3), 9-(2-deoxy-beta- D-erythro-pentofuranosyl)-6-methylpurine (8), and 6-methyl-9-beta-D-ribofur anosylpurine (5) are described. Methodology involving the (Ph3P)(4)Pd catal yzed cross-coupling reaction of CH3ZnBr with several different 6-chloropuri ne derivatives is described in high yield. This methodology now provides a facile and high-yielding synthesis of 8, which is needed in significant amo unts for studies in cancer gene therapy.