Synthesis and Kinetic Study of Hydrolysis of Phosphoric Mono-O- Nitrophenyl Amide in Proton – Rich Media

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Synthetic mono-o-nitrophenyl phosphoric amide (as DCHA Salt ) a C-N-P ester, hydrolyses bimolecularly in acid (0.01-7.0M HCl ) at 40 (±0.5)0C with P-N bond cleavage. Two rate maxima (0.01M & 4.0M HCl ) in acid - rate profile are in favour of the formation of similar type of transition states from the modified - Neutral (or zwitter –ionic) and the Conjugate acid species. Neutral species shows its presence in the low acid range (0.1 to 0.5M HCl ). A rigid and a compact T.S. is decided for the Conjugate acid species, on the basis of DS#, while its low polarity nature is supported by solvent variation study. For synthesis, phosphorylation of the parent amine (with CTAB catalyst) with POCl3 was performed and this was then converted in to the DCHA salt for stability reasons.

Phosphoramidate; C-N-P ester; Hydrolysis; Kinetic stability