A compound of the following formula (I) or a pharmaceutically acceptable salt thereof, wherein R1 and R2 are independently H； R3 is selected from H, a C1-C7 straight-chain, and a branched or cyclic alkyl； and R4, R5, R6, R7, and R8 are each independently selected from C1-C7 alkyl, halo C1-C7 alkyl and the like. Also provided is a method for preparing the compound, pharmaceutical compositions including the compound or pharmaceutically acceptable salts thereof, and uses of the compound or pharmaceutically acceptable salt thereof in the preparation of a medicine for inhibiting HIF prolyl hydroxylase or a medicine for promoting the generation of endogenous EPO.
