The present invention provides compounds of Formula I useful as BACE inhibitors in the treatment of e.g. Alzheimer's disease: wherein A is selected from the group consisting of; of; R
1
is H or F; R
2
is H, —OCH
3
, C1-C3 alkyl; R
3
is H, —CH
3
, or —OCH
3
; and R
4
is H or F; or a pharmaceutically acceptable salt thereof.