There is provided compounds of formula (I), wherein R1, R2, X1, X2, and X3 have meanings given in the description, and pharmaceutically-acceptable salts thereof, which compounds are useful as positron emission tomography (PET) imaging agents, useful in the treatment of diseases in which inhibition of epidermal growth factor receptor tyrosine kinase activity or the inhibition of HER2 activity is desired and/or required, and useful in the treatment of cancer.
                            提供化合物的
化学式(I),其中R1、R2、X1、X2和X3的含义如描述中所述,并其药用盐,这些化合物可用作正电子发射断层扫描(PET)成像剂,适用于治疗需要或必须抑制
表皮生长因子受体
酪氨酸激酶活性或抑制HER2活性的疾病,并适用于癌症的治疗。