1,5,6,7-Tetrahydro-6-thioxo-4H-pyrazolo[3,4-D]pyrimidin-4-one24521-76-4100 % similar Oxipurinol2465-59-059 % similar 4-Amino-6-hydroxypyrazolo[3,4-D]pyrimidine5472-41-342 % similar 4-Amino-1,7-dihydro-6H-pyrazolo[3,4-D]pyrimidine-6-thione23771-52-035 % similar 1H-Pyrazolo[3,4-D]pyrimidin-4-amine2380-63-431 % similar