If someone makes a berachah but says “adeenoi” for Hashem’s name instead of “Ado-noi”, does he fulfill his obligation to make the berachah?
No, he would not fulfill the (full) obligation. The halachic ruling follows the opinion that the Name of Hashem is an integral part of the blessing, and if the Name is articulated in a manner that is patently wrong, it does not fulfill the obligation. However, such a blessing would still fall under the category of thanking Hashem for the food, and would probably not be worse than saying brich Rachmanah mara de’hai pita. Although this does not fulfill the full obligation of the blessing, it is nonetheless a degree of fulfilling the mitzvah.
Sources: See Berachos 40b; Beis Yosef 167; Magen Avraham 187.