SL Green Realty has refinanced the $360 million mortgage on its Midtown Manhattan property at 100 Park Avenue, extending its maturity to December 2027 and securing an additional $70 million. The refinancing retains a 2.25% interest rate, with Newmark and CBRE advising the deal. SL Green also agreed to purchase Prudential Financial’s 49.9% stake in the building, taking full ownership.