Novel compounds

A compound of formula I or a pharmaceutically acceptable salt thereof;

• wherein
• R1 is selected from the group consisting of —(C1-C8)alkyl, —(C2-C8)alkenyl, R42N(C1-C6)alkyl-, R42NC(═O)(C1-C6)alkyl-, R4O(C1-C6)alkyl-, R4OC(═O)(C1-C6)alkyl-, R4C(═O)(C1-C6)alkyl-, R4C(═O)NR4(C1-C6)alkyl-, R42NSO2(C1-C6)alkyl-, R4CSO2NR4(C1-C6)alkyl-, R42NC(═O)NR4(C1-C6)alkyl-, R42NSO2NR4(C1-C6)alkyl-, aryl(C1-C6)alkyl, aroyl(C1-C6)alkyl, heteroaryl(C1-C6)alkyl, heteroaroyl(C1-C6)alkyl, (C3-C8)heterocycloalkyl(C1-C6)alkyl, bicyclic heteroaryl(C1-C6)alkyl and bicyclic heteroaroyl(C1-C6)alkyl;
• R1 moieties comprise unsubstituted —(C2-C8)alkenyl, and —(C1-C8)alkyl unsubstituted or substituted by one or more moieties independently selected from the group consisting of halogen, cyano, acetoxymethyl, and nitro;
• Ar is an optionally substituted aryl moiety;
• R2 is —(C1-C6)alkyl, unsubstituted or substituted on 1-6 carbons by one or more fluorine substituents, or (C3-C6)cycloalkyl;
• R3 is selected from the group consisting of:
• R4 is a moiety independently selected from the group consisting of —H, —(C1-C6)alkyl, —(C2-C6) alkenyl and —(C2-C6)alkynyl;
• R5 moieties are independently selected from the group consisting of —H, —(C1-C6)alkyl, —(C2-C6)alkenyl and heterocyclyl;
• R6 moieties are independently selected from the group consisting of:
• —H, —(C1-C6)alkyl, —(C2-C6)alkenyl and —(C1-C6)alkanoyl, heterocyclyl, heterocyclyl(C1-C3)alkyl, aryl, aryl(C1-C3)alkyl, heteroaryl, heteroaryl(C1-C3)alkyl, bicyclic heteroaryl, and bicyclic heteroaryl(C1-C3)alkyl;
• R5 and R6 may combine to form a 5-7 membered heterocycle;
• X is selected from the group consisting of —C(R5)2—, —NR5—, C(═O)—, —CH2—CH2—, —CH═CH—, —O—, —C(R)(R′)—, and —S(O)n— (where n=0, 1 or 2), where R and R′═(C1-C6)alkyl, OR″, or H, and R″═H or (C1-C6)alkyl;
• and
• Y is nitrogen,
• wherein if R1 represents R42N(C1-C6)alkyl-, wherein both occurrences of R4 represent —(C1-C6)alkyl, then R3 is not acetyl, —NH2, or acetamido.