NIH Chemical Genomics Center, National Human Genome Research Institute, NIH, 9800 Medical Center Drive, MSC 3370, Bethesda, MD 20892-3370, USA.
A series of substituted 3,6-diphenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines were prepared and analyzed as inhibitors of phosphodiesterase 4 (PDE4). Synthesis, structure-activity relationships, and the selectivity of a highly potent analogue against related phosphodiesterase isoforms are presented.