New pharmaceutical compounds

Disclosed is a benzofused five-membered compound of formula I, wherein R2 is in a position ortho to R3 and R1 is in a position ortho to R2 or R1 is in a position ortho to R3 and R4 is in a position ortho to R1. R1 is cyano or nitro, R2 is hydroxy, R3 is hydroxy, R4 is H, alkyl, haloalkyl, cyano, formyl, alkyl-(C=O)-, halogen or nitro and the further substituents are defined in the specification or a pharmaceutically acceptable salt or ester thereof. Also disclosed is the use of said compound for the manufacture of a medicament to treat Parkinson's disease, a method of treating a non-human animal comprising administering said compound and a pharmaceutical composition comprising said compound.