| abstract |
Provided are PDE1 inhibitors of Formula I, processes for their production, their use as pharmaceuticals, and pharmaceutical compositions comprising them. Previous publication WO 2009/075784 disclosed, among others, (6aR,9aS)-2-(4-(6-fluoropyridin-2-yl) benzyl)-5-methyl-3-(phenylamino)-5,6a,7,8,9,9a-hexahydrocyclopenta[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one as an inhibito of PDE1. This compound undergoes significant metabolism at several positions including the aniline ring and the cyclopentane ring. The current invention provides for Compounds of Formula I wherein such metabolism is attenuated by the substitution of hydrogen atoms for deuterium atoms at key locations discovered by the inventors. |