Patent attributes
A compound of formula (I):or a tautomeric form thereof, wherein:R1 represents a hydrogen atom, C1-12 alkyl, C1-12 alkoxy, C1-12 alkylcarbonyl or arylC1-12 alkyl;A1 represents hydrogen or 1 to 4 optional substituents selected from the group consisting of: C1-12 alkyl, C1-12 alkoxy, aryl, and halogen; aryl represents phenyl or naphthyl optionally substituted with up to five groups selected from halogen, C1-12 alkyl, phenyl, C1-12 alkoxy, haloC1-12 alkyl, hydroxy, nitro, C1-12 alkoxycarbonyl, C1-12 alkoxycarbonyl C1-12 alkyl, C1-12 alkoxycarbonyloxy, or C1-12 alkylcarbonyl:A2 represents a benzene ring having 1 to 3 optional substituents selected from hydrogen, halogen, C1-12 alkyl, C1-12 alkoxy; andM− represents a counter-ion other than the maleate ion.
