SL Green Realty closed on a $1.5 billion construction loan for its $3.1 billion office development One Vanderbilt, the real estate investment trust announced Wednesday. Wells Fargo leads the syndicate, which also includes The Bank of New York Mellon, JP Morgan Chase, TD Bank and Bank of China. Landing a loan clears one major hurdle in the way of the 1,401-foot tall, 1.6 million-square-foot office tower set to rise next to Grand Central terminal.