I need an up-and-coming neighborhood south of the loop where wealthy businessmen would live.

Thanks! :)

In the actual South Loop Printer's Row is trendy and rich-y.

Maybe Pilsen or Hyde Park? Not sure exactly what you're going for. I think Pilsen's more artsy and Hyde Park might be too "established." :)

My main characters former love interest - a u of chicago MBA and stockbroker lives south loop (bc he went to u of chicago ;-) ). I was gonna go Hyde park but it just doesn't have that wasn't nuveau riche vibe. Perhaps printers row would be the better choice?

*just doesn't have. Stupid iPhone autocorrect

Try using City Data's Chicago neighborhood map. It links to all kinds of demographic information for each neighborhood, including average income.http://www.city-data.com/nbmaps/neigh-Chicago-Illinois.html