Practical route to a melanin-concentrating hormone receptor 1 (MCHr1) antagonist

ORGN 17

Denise L. Andersen, danderse@amgen.com, Pingli Liu, Thomas Storz, Xin Wang, xinw@amgen.com, Alan Allgeier, Jean Baum, Ying Chen, ying@amgen.com, Rich Crockett, Liang Huang, Robert D. Larsen, rlarsen@amgen.com, and Mike Martinelli. Chemical Process Research and Development, Amgen Inc, One Amgen Center Drive, Thousand Oaks, CA 91320
Melanin-concentrating hormone (MCH) is a 19-amino acid cyclic peptide known to play a role in feeding behaviour. Design of an antagonist for the MCH receptor could provide a drug to control over-eating. The MCHr1 antagonist 1 has been identified as a potential candidate for the treatment of obesity. A synthesis suitable for the large-scale preparation of 1 has been developed. Key features in the synthesis are the preparation of indole 2 via a Fisher indolization reaction and subsequent reductive amination with ester 3 or lactol 4 to afford the target compound. Route definition and optimization of studies will be presented.