Patent ID: 8889671

Claim:
A compound, or a pharmaceutically acceptable salt thereof, wherein the compound has the structure of formula (I): wherein X is fluorine or chlorine; R 1 is selected from the group consisting of hydrogen, phenyl, —C≡N, tetrahydropyranyl, N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl, pyrazinyl, cyclopropyl, —C≡CH, —CH═CH 2 , and C 1 -C 3 alkyl, which C 1 -C 3 alkyl is optionally substituted with one or more of: —OR 10 , halogen, —C≡N, —N 3 , —SO 2 CH 3 , —SCH 3 , —CH═CH 2 , —CH═NOR 11 and phenyl; R 2 is selected from the group consisting of hydrogen, —C≡N, pyridinyl, C 1 -C 3 alkyl, which C 1 -C 3 alkyl is optionally substituted with one or more of: halogen, —OR 20 and —CH═NOR 21 ; R 3 is hydrogen or C 1 -C 3 alkyl; R 10 is for each occurrence independently selected from the group consisting of hydrogen, C 1 -C 4 alkyl and —(CH 2 ) 2 OCH 3 ; and R 11 , R 20 and R 21 are for each occurrence independently hydrogen or C 1 -C 4 alkyl.