Novel indolederivatives of formula (I) or a pharmaceutically acceptable salt thereof:wherein R1is fluorine, or chlorine, and R2is hydrogen, or fluorine, which are SGLT inhibitors and are useful for treatment or prevention of diabetes and related conditions.本發明係一種式(I)之新穎吲哚衍生物或其醫藥上可接受之鹽:其中,R1為氟或氯,且R2為氫或氟,其為SGLT抑制劑,且適用於治療或預防糖尿病及相關病症。