WHEATON, ILL. — Quantum Real Estate Advisors Inc. has brokered the sale of a 14,409-square-foot retail property occupied by Walgreens in Wheaton for $11.6 million. The building was constructed in 2010. Walgreens has roughly 13 years remaining on its lease. Daniel Waszak of Quantum represented the buyer, a private 1031 exchange investor based in New York. A Midwest-based REIT was the seller.