Abstract: | The crystal structures of 1‐{5‐4,6‐bis(methylsulfanyl)‐2H‐pyrazolo3,4‐d]pyrimidin‐2‐yl]pentyl}‐6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo3,4‐d]pyrimidine, C22H29N9S3, and 6‐methylsulfanyl‐1‐{5‐6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo3,4‐d]pyrimidin‐2‐yl]pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo3,4‐d]pyrimidine, C25H34N10S2, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo3,4‐d]pyrimidine rings. |