合成路线1

The amidation of L-serine methyl ester (I) with ethylenediamine (II) gives the amide (III), which is reduced with borane/THF to 2(R)-(hydroxymethyl)diethylenetriamine (IV). The reaction of (IV) with bromoacetic acid tert-butyl ester (V) by means of DIEA in DMF affords the penta tert-butyl acetate (VI), which is condensed with the chlorophosphoramidite (VII) by means of DIEA in dichloromethane giving the phosphoramidite intermediate (VIII). The condensation of (VIII) with 4,4-diphenylcyclohexanol (IX) (see scheme 23537901b) by means of tetrazole in acetonitile, with simultaneous oxidation with tert-butyl hydroperoxide yields the phosphate (X), which is selectively hydrolyzed at the 2-cyanoethyl ester group with ammonia in methanol affording the ammonium phosphate (XI). Finally, the hydrolysis of (XI) with HCl in ether/water eliminates the tert-butyl groups affording the desired chelating ligand (XII)