A series of 1-methyl-7-(4-pyridyl)-5,6,7,8-tetrahydro-3(2H)-isoquinolinones and related compounds were synthesized and evaluated for positive inotropic activity. Most members of this series exerted a dose-dependent increase in myocardial contractility in the dog acute heart failure model, whereas they caused only slight changes in heart rate and blood pressure. Several derivatives, especially those with cyano, acetyl, and ethyl substituents at the 4-position, were more potent than milrinone, which was used as a reference. 4-Acetyl-1-methyl-7-(4-pyridyl)-5,6,7,8-tetrahydro-3(2H)-isoquinolinone (MS-857) is one of the most potent positive inotropic agents in this series.
4‐Substituted cyclohexanone derivatives such as (IV), prepared from the acetal (I) as outlined in the reaction scheme, are acylated, yielding the 2‐acetylcyclohexanones (VI).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.