8-(Acetonylthio)-6-thiotheophylline

8-(Acetonylthio)-1,3-dimethyl-6-thioxo-1,3,6,7-tetrahydro-2H-purin-2-one

6,7-Dihydro-1,3-dimethyl-8-[(2-oxopropyl)thio]-6-thioxo-1H-purin-2(3H)-one