2,7,12,17-Tetrakis(3,5-di-tert-butylphenyl)-21,22,23,24-tetraazapentacyclo[16.2.1.1~3,6~.1~8,11~.1~13,16~]tetracosa-1,3,5,7,9,11(23),12,14,16,18(21),19-undecaene AIDS-135300 AIDS135300 NSC634741