Patent ID: 8865902

Claim:
A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein each of X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , and X 7 is independently hydrogen or deuterium; each of Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , and Y 6 is independently CH 3 or CD 3 ; provided that if each of Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , and Y 6 is CH 3 , then at least one of X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , and X 7 is deuterium.