B6 333 then UA 3906 at San Francisco
Boston → San Francisco → Chicago O'Hare
Timetable, San Francisco time
00:25B6 333 from Boston at the gatealso FI 7897, EY 8015, EY 8328
19:30UA 3906 to Chicago O'Hare leaves the gate
19 h 05 apart on the timetable
UA 3906 leaves 19 h 05 after B6 333 arrives on the timetable: more than half a day, so not a connection we count.