BR 646 then UA 4416 at O'Hare
Anchorage → Chicago → St Louis
Timetable, Chicago time
17:10BR 646 from Anchorage at the gate
15:30UA 4416 to St Louis leaves the gate
22 h 20 apart on the timetable, overnight
UA 4416 leaves 22 h 20 after BR 646 arrives on the timetable: more than half a day, so not a connection we count.