Abstract: A compound having the structures: or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or pharmaceutically acceptable salt, wherein; R selected from the group consisting of H, C1-C6 alkyl, C1-C6 alkoxy and —(CH2)m—W, where W is C3-C8 cycloalkyl, bicycloalkyl, bridged bicycloalkyl, phenyl, 5- or 6-membered heteroaryl or heterocyclic containing one, two or three heteroatoms selected from the group consisting of N, S and O atoms; wherein each of said alkyl, cycloalkyl, alkoxy, heterocyclic, phenyl, naphthyl or heteroaryl may be unsubstituted or substituted by phenyl, halo, cyano, deuterium, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, —SO2—R?, —CONR?R?, NR?COR?, —NR?CONR?R?, —NR?CO2R?, —(CH2)n—SO2—R?, —NHSO2—R?, —NR?SO2—R?, —SO2NR?R?, NR?R? or SR? where R? and R? are independently H, C1-C6 alkyl or C3-C8 cycloalkyl; R1 selected from the group consisting of phenyl, naphthyl, 5- or 6-membered heteroaryl or heterocyclic containing one, two, three or four heteroatoms se