BR 646 then UA 1803 at O'Hare
Anchorage → Chicago → Las Vegas
Timetable, Chicago time
17:10BR 646 from Anchorage at the gate
10:30UA 1803 to Las Vegas leaves the gate
17 h 20 apart on the timetable, overnight
UA 1803 leaves 17 h 20 after BR 646 arrives on the timetable: more than half a day, so not a connection we count.