- Synthesis of [11C]MK-1064 as a new PET radioligand for imaging of orexin-2 receptor
-
The reference standard MK-1064 {5″-chloro-N-((5,6-dimethoxypyridin-2-yl)methyl)-[2,2′:5′,3″-terpyridine]-3′-carboxamide} was synthesized from methyl 2-chloro-5-iodonicotinate and 5-(chloropyridin-3-yl)boronic acid in 4 steps with 33% overall chemical yield. The precursor desmethyl-MK-1064 {5″-chloro-N-((5-hydroxy-6-methoxypyridin-2-yl)methyl)-[2,2′:5′,3″-terpyridine]-3′-carboxamide} for radiolabeling was synthesized from 2-bromopyridin-3-ol and 5″-chloro-[2,2′:5′,3″-terpyridine]-3′-carboxylic acid in 6 steps with 17% overall chemical yield. The target tracer [11C]MK-1064 {5″-chloro-N-((5-[11C]methoxy-6-methoxypyridin-2-yl)methyl)-[2,2′:5′,3″-terpyridine]-3′-carboxamide} was prepared by O-[11C]methylation of its corresponding precursor desmethyl-MK-1064 with [11C]CH3OTf under basic condition and isolated by a simplified solid-phase extraction (SPE) method in 50–60% decay corrected radiochemical yields based on [11C]CO2at end of bombardment (EOB). The overall synthesis time from EOB was 23?min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 185–555?GBq/μmol.
- Gao, Mingzhang,Wang, Min,Zheng, Qi-Huang
-
-
Read Online
- Site-Selective Switching Strategies to Functionalize Polyazines
-
Many drug fragments and therapeutic compounds contain multiple pyridines and diazines. Developing site-selective reactions where specific C-H bonds can be transformed in polyazine structures would enable rapid access to valuable derivatives. We present a study that addresses this challenge by selectively installing a phosphonium ion as a versatile functional handle. Inherent factors that control site-selectivity are described along with mechanistically driven approaches for site-selective switching, where the C-+PPh3 group can be predictably installed at other positions in the polyazine system. Simple protocols, readily available reagents, and application to complex drug-like molecules make this approach appealing to medicinal chemists.
- Dolewski, Ryan D.,Fricke, Patrick J.,McNally, Andrew
-
supporting information
p. 8020 - 8026
(2018/06/01)
-
- Discovery of 5″-chloro-n-[(5,6-dimethoxypyridin-2- yl)methyl]-2,2':5',3″-Terpyridine-3'-carboxamide (mk-1064): A selective orexin 2 receptor antagonist (2-sora) for the treatment of insomnia
-
The field of small-molecule orexin antagonist research has evolved rapidly in the last 15 years from the discovery of the orexin peptides to clinical proof-of-concept for the treatment of insomnia. Clinical programs have focused on the development of antagonists that reversibly block the action of endogenous peptides at both the orexin 1 and orexin 2 receptors (OX1R and OX2R), termed dual orexin receptor antagonists (DORAs), affording late-stage development candidates including Merck's suvorexant (new drug application filed 2012). Full characterization of the pharmacology associated with antagonism of either OX1R or OX2R alone has been hampered by the dearth of suitable subtype-selective, orally bioavailable ligands. Herein, we report the development of a selective orexin 2 antagonist (2-SORA) series to afford a potent, orally bioavailable 2-SORA ligand. Several challenging medicinal chemistry issues were identified and overcome during the development of these 2,5-disubstituted nicotinamides, including reversible CYP inhibition, physiochemical properties, P-glycoprotein efflux and bioactivation. This article highlights structural modifications the team utilized to drive compound design, as well as in vivo characterization of our 2-SORA clinical candidate, 5''-chloro-N- [(5,6-dimethoxypyridin-2-yl)methyl] -2,2':5',3''-terpyridine-3'-carboxamide (MK-1064), in mouse, rat, dog, and rhesus sleep models.
- Roecker, Anthony J.,Mercer, Swati P.,Schreier, John D.,Cox, Christopher D.,Fraley, Mark E.,Steen, Justin T.,Lemaire, Wei,Bruno, Joseph G.,Harrell, C. Meacham,Garson, Susan L.,Gotter, Anthony L.,Fox, Steven V.,Stevens, Joanne,Tannenbaum, Pamela L.,Prueksaritanont, Thomayant,Cabalu, Tamara D.,Cui, Donghui,Stellabott, Joyce,Hartman, George D.,Young, Steven D.,Winrow, Christopher J.,Renger, John J.,Coleman, Paul J.
-
p. 311 - 322
(2014/04/03)
-
- TRIPYRIDYL CARBOXAMIDE OREXIN RECEPTOR ANTAGONISTS
-
The present invention is directed to tripyridyl carboxamide compounds which are antagonists of orexin receptors, and which are useful in the treatment or prevention of neurological and psychiatric disorders and diseases in which orexin receptors are involved. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which orexin receptors are involved.
- -
-
Page/Page column 22-23
(2010/03/02)
-