Quaternary substituted PDE4 inhibitors I: The synthesis and in vitro evaluation of a novel series of oxindoles

The following letter presents the synthesis and in vitro evaluation of a novel quaternary substituted series of phosphodiesterase type (IV) (PDE4) inhibitors. The compounds represent conformationally constrained analogues of the Celltech PDE IV inhibitor, CDP 840. Examples with sub-micromolar IC50ʹs for PDE4 inhibition are reported.