W4 3171 then FR 5301 at Madrid
Bucharest → Madrid → Luxembourg
Timetable, Madrid time
09:45W4 3171 from Bucharest at the gate
07:15FR 5301 to Luxembourg leaves the gate
21 h 30 apart on the timetable, overnight
FR 5301 leaves 21 h 30 after W4 3171 arrives on the timetable: more than half a day, so not a connection we count.