BR 646 then UA 4419 at O'Hare
Anchorage → Chicago → St Louis
Timetable, Chicago time
17:10BR 646 from Anchorage at the gate
12:55UA 4419 to St Louis leaves the gate
19 h 45 apart on the timetable, overnight
UA 4419 leaves 19 h 45 after BR 646 arrives on the timetable: more than half a day, so not a connection we count.