| abstract |
A compound of Formula (Ia): in which R1 represents a group of formula (See formula) in which Z represents O or S, R1-1 represents hydrogen or (C1-C6) alkyl, R1-2 represents hydrogen or alkyl (C1-C6), R1-3 represents hydrogen or (C1-C6) alkyl; R2 represents hydrogen or methyl; or R1 and R2 together may represent a group of formula which, together with the carbons to which said group is attached, forms a carbocyclic ring, where R1-4 represents hydrogen or (C1-C6) alkyl, and R1-5 represents hydrogen or (C1-C6) alkyl; R3 represents hydrogen or methyl; Y represents NR4, O or S; R4 represents hydrogen or (C1-C6) alkyl optionally substituted with 1 or 2 substituents independently selected from the group consisting of (C1-C6) alkoxy and (C6-C10) aryloxy; R5 represents hydrogen, (C1-C6) alkyl, or phenyl optionally substituted with halogen, (C1-C6) alkyl or (C1-C6) alkoxy; |