Reaction SMILES: [CH2:1]([N:12]([CH2:24][C:25]([OH:27])=[O:26])[CH2:13][CH2:14][N:15]([CH2:20][C:21]([OH:23])=[O:22])[CH2:16][C:17]([OH:19])=[O:18])[CH2:2][N:3]([CH2:8][C:9]([OH:11])=[O:10])[CH2:4]C(O)=O.[C:28](CN(CC(=O)NC)CCN(CCN(CC(O)=O)CC(=O)NC)CC(O)=O)(O)=O.C(CN(CC(O)=O)CCNCC(O)=O)(O)=O.C(CN(CC(O)=O)CCN(CCN(CC(O)=O)CC(O)=O)[C@H](C(O)=O)CCC(O)=O)(O)=O.CC(OC(=O)[C@H](CCC(O)=O)N(CCN(CC(OC(C)(C)C)=O)CC(=O)OC(C)(C)C)CCN(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)(C)C.N[C@H](C(O)=O)CCCCN.C(N(CC(O)=O)CC(O)=O)CN(CC(O)=O)CC(O)=O.N1(CC(O)=O)CCNCCN(CC(O)=O)CCN(CC(O)=O)CC1.N1(CC(O)=O)CCCCN(CC(O)=O)CCN(CC(O)=O)CCN(CC(O)=O)CC1.OC(C)CN1CCN(CC(O)=O)CCN(CC(O)=O)CCN(CC(O)=O)CC1>>[C:17]([CH2:16][N:15]([CH2:20][C:21]([OH:23])=[O:22])[C:14]1([CH3:28])[CH2:13][N:12]([CH2:24][C:25]([OH:27])=[O:26])[CH2:1][CH2:2][N:3]([CH2:8][C:9]([OH:11])=[O:10])[CH2:4]1)([OH:19])=[O:18]
Reactant: O=C(O)CN(CCN(CC(=O)O)CC(=O)O)CCN(CC(=O)O)CC(=O)O
Reactant: CNC(=O)CN(CCN(CCN(CC(=O)O)CC(=O)NC)CC(=O)O)CC(=O)O
Agent: CC(C)(C)OC(=O)CN(CCN(CCN(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)[C@@H](CCC(=O)O)C(=O)OC(C)(C)C)CC(=O)OC(C)(C)C
Agent: CC(O)CN1CCN(CC(=O)O)CCN(CC(=O)O)CCN(CC(=O)O)CC1
Agent: NCCCC[C@H](N)C(=O)O
Product: CC1(N(CC(=O)O)CC(=O)O)CN(CC(=O)O)CCN(CC(=O)O)C1

Procedure:
Suitable chelating ligands include those discussed herein, particularly chelating ligands selected from the group consisting of: a polyaminopolycarboxylic acid and the derivative thereof, comprising, for example, diethylenetriamine pentaacetic acid (DTPA) and derivative thereof such as benzo-DTPA, dibenzo-DTPA, phenyl-DTPA, diphenyl-DTPA, benzyl-DTPA, dibenzyl DTPA; N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]amino]ethyl]-glycine (DTPA-BMA); N-[2-[bis(carboxymethyl)amino]-3-(4-ethoxyphenyl)propyl)]-N-[2-[bis(carboxymethyl)amino]ethylglycine (EOB-DTPA); 4-carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-triazamidecan-13-oic acid (BOPTA); N,N-Bis[2-[bis[2-(1,1-dimethylethoxy)-2-oxoethyl]amino]ethyl]L-glutamic acid 1-(1,1-dimethylethyl) ester N,N-bis[2-[bis(carboxymethyl)amino]ethyl]L-glutamic acid (DTPA-GLU); DTPA conjugated with Lys (DTPA-Lys); ethylenediaminetetraacetic acid (EDTA); 1,4,7,10-teraazacyclododecane 1,4,7,-triacetic acid (DO3A); 1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetraacetic acid (DOTA); [10-(2-hydroxypropyl)-1,4,7,10-teraazacyclododecane 1,4,7,-triacetic acid (HPDO3A); 6-[bis(carboxymethyl)amino]tetrahydro-6-methyl-1H-1,4-diazepine-1,4(5H)-diacetic acid (AAZTA) provided by WO03008390 application, incorporated herein by reference, and derivative thereof; 2-methyl-1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetraacetic acid (MCTA); (α,α′,α″,α′″)-tetramethyl-1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetraacetic acid (DOTMA); or a polyaminophosphate acid ligand or derivative thereof, in particular, N,N′-bis-(pyridoxal-5-phosphate) ethylenediamine-N,N′-diacetic acid (DPDP), ethylenedinitrilotetrakis(methylphosphonic) acid (EDTP) or a polyaminophosphonic acid ligand and derivative thereof, or polyaminophosphinic acid and derivative thereof, in particular 1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetrakis[methylphosphonic)] and 1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetrakis[methylene-(methylphosphinic)]acid; or of macrocyclic chelators such as texaphyrins, porphyrins, phthalocyanines.