Patent ID: 8546427

Claim:
A compound of formula (I) wherein R 1 is selected from the group consisting of hydrogen, alkyl, haloalkyl, halogen, cyano and carboxy; R 2 is selected from the group consisting of hydrogen, alkyl, haloalkyl, halogen, cyano and carboxy; R 3 and R 4 are independently alkyl; R 5 and R 6 are independently selected from the group consisting of hydrogen, carboxyalkylamino, carboxycycloalkylamino, alkylsulfonylamino, phenylsulfonylamino, halophenylsulfonylamino, alkylphenylsulfonylamino, phenylcarbonylamino, halophenylcarbonylamino, pyridinylsulfonylamino, alkylaminosulfonyl and halophenylaminosulfonyl; provided that R 5 and R 6 are not both hydrogen at the same time; and R 7 is hydrogen or alkyl; or a pharmaceutically acceptable salt or ester thereof.