| abstract |
The present invention relates to a compound of formula (I) or a pharmaceutically acceptable salt or ester thereof: <Formula I> Where R 1 is H or C 1-2 alkyl; R 2 is H or C 1-3 alkyl; R 3 and R 4 are each independently H or C 1 -2 alkyl, wherein alkyl is selected from R 10, and may be substituted with 1 to 3 same or different substituents; R 5 is H, hydroxy, C 1 -2 alkyl, or OCH 3, and; R 10 is F or Cl. |