A Practical Synthesis of the PDE4 Inhibitor, SB-207499, from a Cyclohexanone Precursor

The synthesis of SB-207499 is described. Investigation and development of new strategies for the homologation of ketone, 4-cyano-4-[3-(cyclopentyloxy)-4-(methoxyphenyl)]-cyclohexan-1-one 2 are described which produce SB-207499. Our ultimate route of synthesis to SB-207499 is robust and operationally simple and produces the final drug substance in good yield and purity.