Jeremy B. Cohen is ankling as associate artistic director of Hartford Stage to become producing artistic director at the Playwrights Center in Minneapolis, beginning the new role in mid-September.It’s the second recent leadership changeup at Hartford, where a.d. Michael Wilson announced last week he is leaving his post at the end of the 2010-11 season, his 13th at the theater, to pursue other projects, most in New York. Hartford’s co-production of Horton Foote marathon “The Orphans’ Home Cycle” went on to have a popular Off Broadway staging last season, and the show is a candidate for a Main Stem transfer. Cohen, who has been at Hartford Stage for six years, is also director of new play development there. Cohen has helmed shows at the theater such as the world preem of a new stage adaptation of “The Adventures of Tom Sawyer,” as well as “Mistakes Were Made,” “Bad Dates” and “I Am My Own Wife,” among others. The associate a.d. post at Hartford Stage helped launch careers of Bartlett Sher, Irene Lewis and Tracy Brigden. Playwrights Center provides a range of services for writers at all stages of their careers.