Patent ID: 8623905

Claim:
A compound of formula II: or a pharmaceutically acceptable salt thereof, wherein independently for each occurrence: R is H, OH, OCH 3 or two R taken together form —CH 2 CH 2 CH 2 —, —OCH 2 O— or —OCF 2 O—; R 1 is H or up to two C1-C6 alkyl; R 2 is H or F; R 3 is H or CN; R 4 is H, —CH 2 CH(OH)CH 2 OH, —CH 2 CH 2 N + (CH 3 ) 3 , or —CH 2 CH 2 OH; and R 5 is H, OH, —CH 2 OCH 2 CH(OH)CH 2 OH, or —CH 2 OH.