Compounds having the general structure III are provided: ##STR00001## where D is N or C; W is selected from ##STR00002## Z.sup.1, Z.sup.2, and Z.sup.3 are independently selected from CR.sup.8 and N; and the other variables have the values described herein. Compounds of formula III have useful properties for controlling diseases related to MC4-R action in humans including obesity and type II diabetes.