Patent ID: 7767860

Claim:
A compound having structural Formula I or a pharmaceutically acceptable salt thereof, wherein: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 , and R 24 are independently selected from the group consisting of hydrogen and deuterium; at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 15 , R 16 , R 17 , R 18 , R 21 , R 22 , R 23 , and R 24 is deuterium; and if R 21 , R 22 , R 23 , and R 24 are each deuterium, then at least one of at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 15 , R 16 , R 17 , and R 18 is deuterium.