2-amino-8-(dimethylamino)-9-(2-hydroxyethoxymethyl)-3H-purin-6-one

2-amino-9-(2-hydroxyethoxymethyl)-8-piperidin-1-yl-3H-purin-6-one

2-[(2-amino-6-oxo-3H-purin-9-yl)methoxy]ethyl benzoate