SAR analysis of novel non-peptidic NPBWR1 (GPR7) antagonists

In this Letter we report on the advances in our NPBWR1 antagonist program aimed at optimizing the 5-chloro-2-(3,5-dimethylphenyl)-4-(4-methoxyphenoxy)pyridazin-3(2H)-one lead molecule previously obtained from a high-throughput screening (HTS)-derived hit. Synthesis and structure–activity relationships (SAR) studies around the 3,5-dimethylphenyl and 4-methoxyphenyl regions resulted in the identification of a novel series of non-peptidic submicromolar NPBWR1 antagonists based on a 5-chloro-4-(4-alkoxyphenoxy)-2-(benzyl)pyridazin-3(2H)-one chemotype. Amongst them, 5-chloro-2-(9H-fluoren-9-yl)-4-(4-methoxyphenoxy)pyridazin-3(2H)-one 9h (CYM50769) inhibited NPW activation of NPBWR1 with a submicromolar IC50, and displayed high selectivity against a broad array of off-targets with pharmaceutical relevance. Our medicinal chemistry study provides innovative non-peptidic selective NPBWR1 antagonists that may enable to clarify the biological role and therapeutic utility of the target receptor in the regulation of feeding behavior, pain, stress, and neuroendocrine function.

Synthesis and structure–activity relationships (SAR) studies around the 3,5-dimethylphenyl and 4-methoxyphenyl regions of our previously identified 5-chloro-2-(3,5-dimethylphenyl)-4-(4-methoxyphenoxy)pyridazin-3(2H)-one lead CYM50557 resulted in the identification of a novel series of non-peptidic submicromolar NPBWR1 (GPR7) antagonists based on a 5-chloro-4-(4-alkoxyphenoxy)-2-(benzyl)pyridazin-3(2H)-one chemotype. 5-chloro-2-(9H-flouren-9-yl)-4-(4-methoxyphenoxy)pyridazin-3(2H)-one 9h (CYM50769) inhibited NPW activation of NPBWR1 with a submicromolar IC50, and displayed high selectivity against a broad array of off-targets with pharmaceutical relevance. The molecules herein reported provide innovative non-peptidic selective NPBWR1 antagonists that may enable to clarify the biological role and therapeutic utility of the target receptor in the regulation of feeding behavior, pain, stress, and neuroendocrine function.Figure optionsDownload as PowerPoint slide