Compounds of the formula I in which R1 and R2 have the meanings indicated in Claim 1, are inhibitors of Tankyrase, and can be employed, inter alia, for the treatment of diseases such as cancer, cardiovascular diseases, central nervous system injury and different forms of inflammation.本發明係關於式I化合物其中R1和R2具有請求項1中所指定之含義,該等化合物係端錨聚合酶(Tankyrase)之抑制劑,且尤其可用於治療諸如癌症、心血管疾病、中樞神經系統損傷及不同形式之炎症之疾病。