| abstract |
A compound of the formula: wherein: A is selected from N and CH, R2a and R2b are independently selected from the group consisting of: (1) hydrogen, (2) fluorine, (3) chlorine, and (4) bromine; R3 is C1-6 alkyl, which is unsubstituted or substituted with fluorine; R4 is selected from the group consisting of: (1) hydrogen, and (2) C1-3 alkyl; one of X and Y is selected from the group consisting of: (1) 18F, (2) -O (11CH3), and (3) -O (CD2 18F), and the other of X and Y is hydrogen; or a pharmaceutically acceptable salt thereof or an individual enantiomer or diastereomer thereof. |