FR 4596 then EC 4212 at Barcelona
Porto → Barcelona → Napoli
Timetable, Barcelona time
00:50FR 4596 from Porto at the gate
17:35EC 4212 to Napoli leaves the gate
16 h 45 apart on the timetable
EC 4212 leaves 16 h 45 after FR 4596 arrives on the timetable: more than half a day, so not a connection we count.