“…6,6'-Bis (1,4,8,11-tetraazacyclotetradecane-5,7-dione) was initially prepared in similar manner to that described by Fabbrizzi et al [18] ,8.43;N,24.65. Found: C,52.98;H,8.11;N,24.76. This compound was then converted to 9 using the published procedure [18] ,11.63;N,27.80. Found: C,59.34;H,11.12;N,27.56.…”