Chemical and Pharmaceutical Bulletin
Online ISSN : 1347-5223
Print ISSN : 0009-2363
ISSN-L : 0009-2363
Imidazo[1, 2-α]pyridines. II. Ozonolysis of Imidazo[1, 2-α]pyridines and Synthesis of Carfiotonic Agents
Motosuke YAMANAKAShinji SUDANaoki YONEDAHideto OHHRA
Author information
JOURNAL FREE ACCESS

1992 Volume 40 Issue 3 Pages 666-674

Details
Abstract
The metabolite of loprinone (E-1020) in dogs, 5-(2-aminopyridin-5-yl)-1, 2-dihydro-6-methyl-2-oxo-3-pyridine-carbonitrile (9), was prepared via ozonolysis of imidazo[1, 2-α]pyridinylpyridines and evaluated for positive inotropic activity. Its potency was less than that of loprinone and milrinone. Among compounds related to loprinone which were synthesized using the versatile intermediates (10a, b) obtained during the preparation of 9, only 5-(2-aminoimidazo[1, 2-α]pyridin-6-yl)-1, 2-dihydro-6-methyl-2-oxo-3-pyridinecarbonitrile (27) retained the activity of loprinone. The electron-withdrawing substituents at hte 2-position of imidazo[1, 2-α]pyridine reduced the activity of the parent compound.The ozonolysis of imidazo[1, 2-α]pyridine derivatives under neutral confitions afforded 2-acylaminopyridine derivatives in a 30-55% yield independent of the substituents at the 2-position of imidazo[1, 2-α]pyridine. It is possible to use imidazo[1, 2-α]pyridine as protected 2-aminopyridines, and 2, 3-unsubstituted imidazo[1, 2-α]pyridines are convenient for that purpose from the viewpoint of ease of preparation of the starting material.
Content from these authors
© The Pharmaceutical Society of Japan
Previous article Next article
feedback
Top