1-p-Nitrophenyl-ethylenediaminetetracetic acid → 12-Amino-phenyl-edta

Reaction equation

[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH:10]([N:21]([CH2:26][C:27]([OH:29])=[O:28])[CH2:22][C:23]([OH:25])=[O:24])[CH2:11][N:12]([CH2:17][C:18]([OH:20])=[O:19])[CH2:13][C:14]([OH:16])=[O:15])=[CH:6][CH:5]=1)([O-])=O.[H][H]>[OH-].[Na+].[Pd].C>[NH2:1][C:4]1[CH:9]=[CH:8][C:7]([CH:10]([N:21]([CH2:26][C:27]([OH:29])=[O:28])[CH2:22][C:23]([OH:25])=[O:24])[CH2:11][N:12]([CH2:17][C:18]([OH:20])=[O:19])[CH2:13][C:14]([OH:16])=[O:15])=[CH:6][CH:5]=1

Participants

Procedure

43 mg, 0.10 mmol of 1-(p-Nitrophenyl)-ethylenediaminetetraacetic acid was dissolved in 50 ml of aqueous NaOH (such that the final pH was 9), and 29 mg of 10% Pd/charcoal catalyst was added. The mixture was stirred gently for 5 hr in an ice bath under 1 atm of hydrogen. The catalyst was removed by filtration, and the filtrate was evaporated to dryness. In D2O, the aromatic region of the 60 MHz nmr spectrum of the 1-(p-Aminophenyl)-ethylenediaminetetraacetic acid product consisted of an aa'bb' pattern centered 7.0 ppm downfield from Me4Si. The differences in the nmr spectra of the products of Steps V and VI make it convenient to monitor the progress of the reduction by nmr. By this criterion, the reduction was quantitative. The product was stored in the dark at -15°.