FR 4596 then FR 6330 at Barcelona
Porto → Barcelona → Sofia
Timetable, Barcelona time
00:50FR 4596 from Porto at the gate
17:15FR 6330 to Sofia leaves the gate
16 h 25 apart on the timetable
FR 6330 leaves 16 h 25 after FR 4596 arrives on the timetable: more than half a day, so not a connection we count.