Referenced in: none

Automatically associated channels: TRP , TRPV , TRPV1

Title: 1,2-diamino-ethane-substituted-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepines as TRPV1 antagonists with improved properties.

Authors: Alec D Lebsack, Jason C Rech, Bryan J Branstetter, Natalie A Hawryluk, Jeffrey E Merit, Brett Allison, Raymond Rynberg, Johnathan Buma, Michele Rizzolio, Nadia Swanson, Hong Ao, Michael P Maher, Michelle Herrmann, Jamie Freedman, Brian P Scott, Lin Luo, Anindya Bhattacharya, Qi Wang, Sandra R Chaplan, Alan D Wickenden, J Guy Breitenbucher

Journal, date & volume: Bioorg. Med. Chem. Lett., 2010 Dec 1 , 20, 7142-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/20932750

Abstract
Based upon a previously reported lead compound 1, a series of 1,2-diamino-ethane-substituted-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepines were synthesized and evaluated for improved physiochemical and pharmacokinetic properties while maintaining TRPV1 antagonist activity. Structure-activity relationship studies directed toward improving the aqueous solubility (pH 2 and fasted-state simulated intestinal fluid (SIF)) and rat pharmacokinetics led to the discovery of compound 13. Aqueous solubility of compound 13 (pH 2 ≥237 μg/mL and SIF=11 μg/mL) was significantly improved over compound 1 (pH 2=5 μg/mL and SIF=0.5 μg/mL). In addition, compound 13 afforded improved rat pharmacokinetics (CL=0.7 L/kg/h) compared to compound 1 (CL=3.1 L/kg/h). Compound 13 was orally bioavailable and afforded a significant reversal of carrageenan-induced thermal hyperalgesia at 5 and 30 mg/kg in rats.