| abstract |
A compound of Formula I, said compound of Formula I being a compound of Formula I(a), I(b), I(c) or I(d): **(See formula)** or a pharmaceutically acceptable salt thereof same, wherein: R1, R2, R3 and R4 are hydrogen; R5 is hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, C0-C4 (C3-C6 cycloalkyl), or C1-C6 heteroalkyl; R6 is hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, or C0-C4 (C3-C6 cycloalkyl); and R7 and R8 are each independently selected from hydrogen or C1-C6 alkyl. |