1. bThe present article is also the first original report of the synthetic study of MCOPPB and its analogues herein.
2. cThe details of a study of NOP receptor agonist as analgesic with a different series of analogues including those in ref1awill be reported ( Hayashi, S.; et al.).
3. aThe details of the SAR study of the NOP agonists in this article for potent anxiolytic activity, little hERG binding affinity, and metabolic stability will be reported as a subsequent article. ( Hayashi, S.; et al.).
4. bSee also ref61.