Vinylogous acid derivatives

A Compound of formula (I)

• wherein
• A is selected from the group consisting of —CH2—, —O— and —NR′—, wherein R′ is selected from the group consisting of hydrogen and C1-6 alkyl, or wherein R′ and R4 form C2-5 alkylene;
• R1 is selected from the group consisting of hydrogen, halogen, nitro, cyano, amino, C1-6 alkyl, heteroalkyl, C3-7 cycloalkyl, C2-6 alkenyl, C2-6 alkynyl, hydroxy, C1-6 alkoxy, —NR′R″, —(C0-6 alkylene)-NR′R″, wherein R′ and R″ are independently selected from the group consisting of hydrogen, C1-6 alkyl, heteroalkyl, formyl, C1-6 alkylcarbonyl, optionally substituted C3-7 cycloalkylcarbonyl, optionally substituted arylcarbonyl, optionally substituted heteroarylcarbonyl, optionally substituted heterocyclylcarbonyl, C1-6 alkylsulfonyl, optionally substituted C3-7 cycloalkylsulfonyl, optionally substituted arylsulfonyl, optionally substituted heteroarylsulfonyl and optionally substituted heterocyclylsulfonyl, and —(C0-6 alkylene)-OR′, wherein R′ is selected from the group consisting of hydrogen, C1-6 alkyl, heteroalkyl, formyl and C1-6 alkylcarbonyl;
• R2, R2′ and R2″ are independently selected from the group consisting of hydrogen, halogen, cyano, nitro, amino, mono- or di-C1-6 alkyl substituted amino, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, heteroalkyl, hydroxy and C1-6 alkoxy;
• R3 is selected from the group consisting of hydrogen, halogen, cyano, nitro, amino, mono- or di-C1-6 alkyl substituted amino, C1-6 alky, C2-6 alkenyl, C2-6 alkynyl, heteroalkyl, hydroxy, C1-6 alkoxy, optionally substituted C3-7 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted C3-7 cycloalkyl-C1-6 alkyl, optionally substituted aryl-C1-6 alkyl, optionally substituted heteroaryl-C1-6 alkyl and optionally substituted heterocyclyl-C1-6 alkyl;
• R4 is selected from the group consisting of hydrogen, halogen, cyano, nitro, amino, mono- or di-C1-6 alkyl substituted amino, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, heteroalkyl, hydroxy, C1-6 alkoxy, optionally substituted C3-7 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted C3-7 cycloalkyl-C1-6 alkyl, optionally substituted aryl-C1-6 alkyl, optionally substituted heteroaryl-C1-6 alkyl and optionally substituted heterocyclyl-C1-6 alkyl;
• R5 is selected from the group consisting of hydrogen and C1-6 alkyl;
• or
• R4 and R5, together with the carbon atom to which they are attached, form an optionally substituted C3-7 cycloalkyl ring or an optionally substituted heterocyclyl ring;
• R6 is selected from the group consisting of hydrogen and C1-6 alkyl;
• or a pharmaceutically acceptable salt thereof.