Good evening,
which evidence do you have to state that he died in Kassel?
One source for this family:
Hassel, Deutsches Familienarchiv, Band 77:
Beiträge zur Genealogie Altfrankfurter Hugenottenfamilien; Ahnenliste A: de Bary.
......
Hassel, Johann Friedrich, Bürger und Goldschmied in Kassel, * Ffm 3.9.1620, † ..., ∞ Ffm 25.12.1648
his wife
Nicq, Sara, * Ffm 25.10.1625, † ...
his father
Hassel, Friedrich, Bürger 1614 und Goldschmied in Ffm, * ebd. ..., † ... vor 1635, ∞ Ffm 26.5.1615
(* = born
† = deceased
∞ = married;
Ffm = Frankfurt am Main)
Kind regards, Vera