You don't want to be in East St. L, it's true, but it's pretty hard to accidentally wind up there -- it's on the other side of the Mississippi from where you'll be. What you might want to keep an eye out for is north St. Louis -- it doesn't have a nice clean border like the east side does.
Basically the further west you go, the farther north you can safely go. Anywhere straight west and south of where you'll be is urban, but fairly safe. Feel free to PM me and I'll give you some tips on where to go to eat or shop if you have the time.
Greekgrrl