(S)-7-(2-fiuoropyridin-3-yl)- 3-(neopentyloxy)-2',6'-dihydrospiro[chromeno[2,3-c]pyridine-5,3'-[1,4]oxazin]-5'-amine

(S)-7-bromo-3-methoxy-2',6'-dihydrospiro[chromeno[2,3-c]pyridine-5,3'-[1,4]oxazin]-5'-amine

(5S)-3-(3,6-dihydro-2H-pyran-4-yI)-7-(2-fIuoro-3-pyridinyl)-6H-spiro[chromeno[2,3-c]pyridine-5,3-[1,4]oxazin]-5-amine

(5S)-7-(2-fluoro-3-pyridinyl)-3-(tetrahydro-2H-pyran-4-yl)-6H-spiro[chromeno[2,3-c]pyridine-5,3-[1,4]oxazin]-5-amine