Patent ID: 8012969

Claim:
A compound of formula I: or a pharmaceutically acceptable salt thereof, wherein X is CH or N; Y is —C(OR 1 )(R 2 ) 2 or —N(R 3 ) 2 ; R 1 is H or C 1 -C 6 alkyl; each R 2 is independently C 1 -C 6 alkyl, or both R 2 groups are taken together form —(CH 2 ) n —, where n is an integer ranging from 2 to 7; each R 3 is independently C 1 -C 6 alkyl, or both R 3 groups are taken together to form —(CH 2 ) 2 —O—(CH 2 ) 2 —, —(CH 2 ) 2 —(NR 4 )—(CH 2 ) 2 — or —(CH 2 ) m —, where m is an integer ranging from 2 to 7; R 4 is H or CH 3 ; and * is a chiral carbon atom, wherein the carbon is a racemate, an (R)-enantiomer, an (S) -enantiomer, or a mixture thereof.