Inhibitors of glutaminyl cyclase

A compound of formula (I),

• or a pharmaceutically acceptable salt, including all tautomers and stereoisomers thereof wherein:
• R1 represents alkenyl, wherein the double bond is not adjacent to the nitrogen;
• carbocyclyl;
• —C1-6alkyl-carbocyclyl;
• heterocyclyl;
• —C1-6alkyl-heterocyclyl;
• aryl;
• heteroaryl;
• —C1-6alkylaryl;
• —C1-6alkylheteroaryl;
• -phenyl fused to carbocyclyl or -phenyl fused to heterocyclyl;
• in which any of the aforesaid carbocyclyl and heterocyclyl groups may optionally be substituted by one or more groups selected from methyl and oxo;
• and
• in which any of the aforesaid phenyl, aryl and heteroaryl groups may optionally be substituted by one or more substituents selected from C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C1-6haloalkyl, —C1-6thioalkyl, —SO2C1-4-alkyl, C1-6alkoxy-, —O—C3-8cycloalkyl, C3-8cycloalkyl,
• —SO2C3-8cycloalkyl, C3-6alkenyloxy-, C3-6alkynyloxy-, —C(O)C1-6-alkyl, C1-6alkoxy-C1-6alkyl-, nitro, halogen, cyano, hydroxyl, —C(O)OH, —NH2, —NHC1-4-alkyl,
• —C(O)N(C1-4alkyl)(C1-4alkyl), —C(O)NH2, —C(O)NH(C1-4alkyl), —C(O)OC1-6alkyl, —SOC1-4alkyl and —SOC3-6cycloalkyl;
• or
• R1 represents phenyl substituted by phenyl, or phenyl substituted by an optionally substituted monocyclic heteroaryl group in which any of the aforesaid phenyl and monocyclic heteroaryl groups may optionally be substituted by one or more groups selected from C1-4alkyl, halogen and C1-4alkoxy;
• or
• R1 represents phenyl substituted by benzyloxy- in which any of the aforesaid phenyl or benzyloxy groups may optionally be substituted on the ring by one or more groups selected from C1-4alkyl, halogen and C1-4alkoxy;
• and
• A represents
• wherein Y represents a C2-5 alkylene chain, which may optionally be substituted by one or two methyl groups or may optionally be substituted by two alkylene substituents at the same position wherein the two alkylene substituents are joined to each other to form a C3-5-spiro-cycloalkyl group and
• R2, R3 and R4 independently represent H or C1-2alkyl, provided that R2 and R3 and R4 do not all represent H;
• or
• A represents
• wherein Z represents a bond, —CH2—, —CH2—CH2—, —CH(Me)- , —CH(Me)-CH2— or —CH2—CH(Me)- and
• R5 and R6 independently represent H or C1-2alkyl and
• B represents H or methyl.