{9-[4-(1-amino-cyclobutyl)-phenyl]-8-phenyl-9H-purin-2-yl}-methyl-amine

[1-(4-{2-[2-methyl-3-(2-trimethylsilanyl-ethoxymethyl)-3H-imidazol-4-yl]-8-phenyl-purin-9-yl}-phenyl)-cyclobutyl]-carbamic acid tert-butyl ester

1-{4-[2-(2-methyl-3H-imidazol-4-yl)-8-phenyl-purin-9-yl]-phenyl}-cyclobutylamine

{1-[4-(2-methylcarbamoyl-8-phenyl-purin-9-yl)-phenyl]-cyclobutyl}-carbamic acid tert-butyl ester

9-[4-(1-amino-cyclobutyl)-phenyl]-8-phenyl-9H-purine-2-carboxylic acid methyl-amide