Eli Lilly and Company
[1,2,4]TRIAZOLO[4,3-A]PYRAZIN-8-ONE DERIVATIVES

Abstract:

The present invention provides a compound of Formula I: wherein R.sup.1 is methyl, ethyl or cyclopropyl; R.sup.2 is hydrogen, methyl, or ethyl; R.sup.3 is methyl or AA; and R.sup.4 is C2-C4 alkyl, BB; or a pharmaceutically acceptable salt thereof; for use as a PDE1 inhibitor. ##STR00001##