FR 4596 then TK 1852 at Barcelona
Porto → Barcelona → Istanbul
Timetable, Barcelona time
10:55FR 4596 from Porto at the gate
06:30TK 1852 to Istanbul leaves the gate
19 h 35 apart on the timetable, overnight
TK 1852 leaves 19 h 35 after FR 4596 arrives on the timetable: more than half a day, so not a connection we count.