Separation of the crude reaction mixture by preparative HPLC using a gradient of MeCN and water (with 0.05% v/v TFA) on a reversed-phase column was sufficient to purify the target molecule 7 on a semipreparative scale to >96% according to analytical HPLC. The photochromic cAMP derivative 7 is an orange powder after lyophilization and is stored for several months at -18 °C without noticeable degradation.