Patent ID: 6878704

Claim:
A compound of formula (IA) or (IB): in which: R 1 is: a 5- or 6-membered aromatic or heteroaromatic ring attached via a ring carbon atom and having a substituent selected from halo, R 7 O—, R 7 S— or R 8 R 9 N— on a ring carbon adjacent to the carbon of attachment; or a 5- or 6-membered dihydro heteroaromatic ring attached via a ring carbon atom and having one oxygen or one or two nitrogen atoms and optionally fused to phenyl, a 5- or 6-membered heteroaryl ring having one or two nitrogen atoms or a 5- or 6-membered heterocyclyl ring having a sulphur, oxygen or nitrogen atom and further having a substituent selected from oxo or thioxo on a ring carbon adjacent to the carbon of attachment; a 6-membered tetrahydro heteroaromatic ring attached via a ring carbon atom having one or two nitrogen atoms and further having two substituents independently selected from oxo or thioxo wherein one of the substituents is on a ring carbon adjacent to the carbon of attachment; or a bicyclic heteroaryl ring attached via a ring carbon atom and having nine or ten ring atoms and from one to four nitrogen atoms; wherein the ring of R 1 may be optionally further substituted; R 2 is vinyl or ethyl; R 3 is H, OH or F and R 4 is H, or R 3 is H and R 4 is F and R 5 and R 6 together form an oxo group; or R 3 and R 4 is each H and R 5 is H, or OH and R 6 is H or R 5 is H and R 6 is H or OH; R 7 is optionally substituted C (1-6) alkyl; and R 8 and R 9 are independently selected from hydrogen or optionally substituted C (1-6) alkyl.