It’s Διάδοχοι so rather Dee-AH-Do-©hee with accent on A, actually more like thee-AH-do-hee but that might sound a bit weird if you don’t have a feel for greek pronounciation. A small tip is that “i” is never pronounced as in “die” in greek but as “ee” (or as in “tin” if short).

Edit: I know modern greek, not ancient. The χ might have been more like a K (as the end of truck) in ancient times but I’m not sure. My suggestion above would be a lot closer to the correct pronunciation though.

Dee-AH-doh-kee like in ancient greek is probably what you want to use. Sorry for the confusion.