JDL Development and investment partner Kayne Anderson Real Estate have reached a deal to buy roughly 31 acres on the north end of the stalled Lincoln Yards project along the Chicago River, the companies said Thursday. The purchase price was not disclosed, and the partners expect to complete the transaction by the end of September, pending city approvals. The site will be rebranded Foundry Park and recast as a walkable residential neighborhood with an estimated 2,000 to 3,000 units spanning single-family homes, condominiums, rental apartments and affordable housing. JDL chief executive Jim Letchinger said the plan favors mid-rise buildings, limited retail space and possibly one high-rise of about 40 stories; office towers have been dropped from the blueprint. The scaled-back concept replaces Sterling Bay’s abandoned vision for a 14-million-square-foot, $6 billion mixed-use complex that would have relied on significant new infrastructure and tax-increment financing. JDL argues that a smaller footprint will cut traffic, avoid costly bridge construction and allow tax dollars earmarked for the project’s infrastructure to be redeployed elsewhere. City planners and neighborhood groups will review the proposal in the coming months. Alderman Scott Waguespack, whose ward includes the site, said he will work with community members to refine the design, while local economic-development advocates urged the developer to blend housing with job-creating uses such as small-scale industrial or retail operations.