The two companies join a growing list of tenants in the 2.8 million-square-foot building at 433 W. Van Buren St., which is being redeveloped into offices in a $800 million-plus project by New York-based 601W Cos. Based on hiring projections provided from companies that have signed leases, there are already plans to bring about 3,300 employees into the building in the next few years — with the majority of the space yet to be leased.