Samuel Zangen, his wife Chawa and their only son Mendel (also called Jules), aged 14, left Antwerp in August 1942 in order to reach a safe haven in Switzerland. They were arrested on August 21 by German border guards while attempting to cross the border from occupied France to Switzerland, a little south of Morteau (Dept Doubs), between French Montlebon and Swiss Le Gardot. They were put into jail in Pontarlier, transferred on August 28 to the German section of the prison in Besançon, then to camp Pithiviers, and finally to Drancy. Samuel and Chawa Zangen were deported to Auschwitz on September 18, 1942 (convoy 34).
Mendel was separated from his parents either in Pithiviers or in Drancy, and taken into care by the UGIF in one of its homes for abandoned children in Paris; maybe he later went into hiding. One year later, Mendel was exfiltrated from Paris and brought to Switzerland (through the border in Geneva) by the Mouvement de la jeunesse sioniste (French Zionist Youth movement), where he safely arrived on September 8, 1943, in a group of 14 children.
Sources:
Archives départementales du Doubs, 1409 W 28
Archives d'Etat de Genève, Justice et Police Ef/2-4565
Archives de l'OSE, Liste des enfants passés en Suisse