The present invention relates to general formula [I] compound represented or its pharmaceutically acceptable salts or ester. In formula (I), R1 and R2 are identical or different, indicate hydrogen atom, low alkyl group, naphthenic base etc.； R3 and R4 are identical or different, indicate hydrogen atom, low alkyl group, NRaRb, phenyl, the low alkyl group being substituted by phenyl, 4 yuan~7 yuan of aliphatic heterocyclyl radical, by low alkyl group, 5 yuan~6 yuan of aromatic heterocyclic radical, the low alkyl group replaced by 5 yuan~6 yuan of aromatic heterocyclic radical that 4 yuan~7 yuan of aliphatic heterocyclyl radical replaces etc.； R5 indicates hydrogen atom, cyano, halogen atom or low alkyl group.本發明涉及通式[I]所示的化合物或其藥學上可接受的鹽或酯。式 (I)中，R1和R2相同或不同，表示氫原子、低級烷基、環烷基等；R3和R4相同或不同，表示氫原子、低級烷基、NRaRb、苯基、被苯基取代的低級烷基、4元～7元的脂肪族雜環基、被4元～7元的脂肪族雜環基取代的低級烷基、5元～6元的芳族雜環基、被5元～6元的芳族雜環基取代的低級烷基等；R5表示氫原子、氰基、鹵原子或低級烷基。
