... In searching for exogenous ligands to explore the function of GPR139, Shi et al.(7) have reported on a series of benzohydrazides as potent and selective agonists ... NEt, DCM; (b) 4 M HCl, dioxane; (c) R 1 ArCOCl, Et 3 N, DCM; (d) Boc-NHCH 2 CHO, NaBH(OAc) 3 , DCM; (e) 4 M ...