Rentech, Inc., purchased the 14,400-square-foot flex building at 521 Great Road in Littleton, MA, for $1,080,000 or $75 per square foot. Located a half mile from the 495/Route 119 interchange, the building features 2 loading docks, 12'-14' ceilings, and parking at a ratio of 3.5 per 1,000 square feet. Rentech manufactures high purity gas and fluid piping systems used in processes for the semi-conductor, biotech and pharmaceutical industries. The seller, Craig Foster, a private investor based in Portland ME, and Rentech were both represented in the transaction by Micah, James, and David Stubblebine of The Stubblebine Co.