Patent ID: 8410104

Claim:
A compound of formula I, wherein R 1 is lower alkyl or lower alkyl substituted by 1-5 substituents individually selected from amino, halogen, (lower alkyl, lower alkyl)N— and (lower alkyl, H)N—; R 2 is H, lower alkyl or lower alkyl substituted by 1-5 substituents individually selected from amino, halogen, halogen-lower alkoxy, hydroxy, lower alkoxy, (lower alkyl, lower alkyl)N—, (lower alkyl, H)N—, nitro and lower alkyl-S(O) 2 —; R 3 is H, lower alkyl or lower alkyl substituted by 1-5 substituents individually selected from amino, halogen, halogen-lower alkoxy, hydroxy, lower alkoxy, (lower alkyl, lower alkyl)N—, (lower alkyl, H)N—, nitro and lower alkyl-S(O) 2 —; R 4 is selected from the group consisting of i) H, ii) lower alkyl, iii) lower alkyl substituted by 1-5 substituents individually selected from amino, halogen, halogen-lower alkoxy, hydroxy, lower alkoxy, (lower alkyl, lower alkyl)N—, (lower alkyl, H)N—, nitro and lower alkyl-S(O) 2 —; iv) heterocyclyl, and v) heterocyclyl substituted by 1-4 substituents individually selected from amino, halogen, halogen-lower alkoxy, halogen-lower alkyl, hydroxy, hydroxy-lower alkyl, lower alkoxy, lower alkoxy-lower alkyl, lower alkyl, (lower alkyl, lower alkyl)N—, (lower alkyl, H)N—, nitro and lower alkyl-S(O) 2 —; or a pharmaceutically acceptable salt or ester thereof.