BR 646 then UA 4576 at O'Hare
Anchorage → Chicago → St Louis
Timetable, Chicago time
09:50BR 646 from Anchorage at the gate
22:00UA 4576 to St Louis leaves the gate
12 h 10 apart on the timetable
UA 4576 leaves 12 h 10 after BR 646 arrives on the timetable: more than half a day, so not a connection we count.