LA 1840 then CX 1751 at Madrid
Santiago de Compostela → Madrid → Buenos Aires
Timetable, Madrid time
22:55LA 1840 from Santiago de Compostela at the gatealso AV 2573, VY 5736, AA 8551
12:10CX 1751 to Buenos Aires leaves the gatealso BA 4255, AY 5375
13 h 15 apart on the timetable, overnight
CX 1751 leaves 13 h 15 after LA 1840 arrives on the timetable: more than half a day, so not a connection we count.