Quinoline derivatives

A compound of formula I or a pharmaceutically acceptable salt or ester thereof wherein formula I is:

• wherein:
• R1 is —O—R4 or —NR5R6;
• R2 is hydrogen, alkyl, cycloalkyl, alkoxy, halogen, heterocyclyl or amino;
• R3 is hydrogen, alkyl, amino or halogen;
• R4 is hydrogen, alkyl, cycloalkyl, aryl, aralkyl, cycloalkylalkyl, alkoxyalkyl, hydroxyalkyl or heterocyclyl;
• R5 and R6 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, cycloalkylalkyl, alkoxyalkyl, hydroxyalkyl and heterocyclyl;
• or R5 and R6 together with the N atom to which they are attached form a 5- to 10-membered heterocyclic ring optionally containing a second heteroatom selected from the group consisting of nitrogen, oxygen and sulfur, wherein the heterocyclyc ring is optionally substituted with one or more substituents independently selected from the group consisting of alkyl and alkoxy;
• A1 is a 5- to 7-membered saturated heterocyclic ring optionally containing a second heteroatom selected from the group consisting of oxygen, sulfur and nitrogen, with the proviso that the A1 ring is not azepan, piperidine or pyrrolidine, and wherein the A1 ring is optionally substituted by one to three substituents independently selected from the group consisting of alkyl, alkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amino, acetylamino, cyano, tetrahydropyranyloxyalkyl and cycloalkylalkoxy;
• and
• A2 is —CH2— or —C(O)—.