Oak Lawn, Ill. — Quantum Real Estate Advisors Inc. has brokered the $3.5 million sale of a 13,000-square-foot retail building in the Chicago suburb of Oak Lawn. Built in the mid-2000s and known as 51st Avenue Station, the property was fully leased at the time of sale to Chiro One, Miracle One, Cold Stone Creamery and other local and national tenants. Chad Firsel and Brett Berlin of Quantum represented the seller, a private fund based in Illinois, in the 1031 exchange.