1 6AJ 2-({2-[(3r)-3-aminopiperidin-1-yl]-5-methyl-6,9-dioxo-5,6,7,9-tetrahydro-1h-imidazo[1,2-a]purin-1-yl}methyl)-4-fluorobenzonitrile 1.000 2 XIH 2-({8-[(3r)-3-aminopiperidin-1-yl]-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7h-purin-7-yl}methyl)benzonitrile 0.743