DTPA ESTERS WITH ORTHOGONAL REMOVABLE PROTECTING GROUPS

摘要

The synthesis of compounds of formula (XXXIII) wherein each R4 is a removable protecting group; R5 is a removable protecting group different from and removable separately from R4; each R6 and R8 is a linking moiety having 1 to 10 carbon atoms; and R9 is hydrogen or a C1 to C50 alkyl moiety; is disclosed. These compounds are useful intermediates in the synthesis of compounds of formula (X). These compounds are useful in the preparation of nuclear pharmaceuticals such as those used for tumor imaging or tumor therapy.