Selective protection of 1,4,8,11-tetraazacyclotetradecane (cyclam) in position 1,4 with the phosphonothioyl group and synthesis of a cyclam-1,4-bis(methylphosphonic acid). Crystal structures of several cyclic phosphonothioamides
1,4-protected cyclam was prepared by reaction with phenylphosphonothioic dichloride and used for synthesis of cyclam-1,4-bis(phosphonic acid). Crystal structures of the target ligand as well as several phosphonothioic intermediates were determined.