B6 778 then UA 563 at Boston
Las Vegas → Boston → Chicago O'Hare
Timetable, Boston time
05:00B6 778 from Las Vegas at the gate
17:02UA 563 to Chicago O'Hare leaves the gate
12 h 02 apart on the timetable
UA 563 leaves 12 h 02 after B6 778 arrives on the timetable: more than half a day, so not a connection we count.