68161-17-1 AIDS-128555 AIDS128555 NSC286714 Spiro(9H-fluorene-9,3'-pyrrolidine)-2',5'-dione, 1'-(1-piperidinylmethyl)- {Spiro[9H-fluorene-9,3'-pyrrolidine]-2',} 5'-dione, 1'-(1-piperidinylmethyl)-