Reactions of Bis(2,4-dinitrophenyl) Phosphate with Hydroxylamine

Abstract

For dephosphorylation of bis(2,4-dinitrophenyl) phosphate (BDNPP) by hydroxylamine in water, pH region 4-12, the observed first-order rate constant, k(obs), initially increases as a function of pH, but is pH-independent between pH 7.2 and pH 10. The initial BDNPP cleavage by nonionic NH(2)OH (<0.2 M) involves attack by the OH group and follows first-order kinetics, but the overall initial reaction of BDNPP liberates ca. 1.7 mol of 2,4-dinitrophenoxide ion (DNP). This initial reaction generates a short-lived O-phosphorylated hydroxylamine, 2, followed by three possible reactions: (1) reaction of 2 with hydroxylamine, generating 2,4-dinitrophenyl phosphate (DNPP, 3), which subsequently forms DNP; (2) intramolecular displacement of the second DNP group and rapid decomposition of the cyclic intermediate to form phosphonohydroxylamine and eventually inorganic phosphate; (3) a novel rearrangement with intramolecular aromatic nucleophilic substitution involving a cyclic intermediate and migration of the 2,4-dinitrophenyl group from O to N. Values of k(obs) increase modestly with pH > 10, the reaction is biphasic, and the yield of DNP increases. An increase in [NH(2)OH] also increases the yield of DNP, due largely to accelerated hydrolysis of DNPP.

Reactions of alpha-nucleophiles with a model phosphate diester

“…In the presence of hydroxylamine at pH 7 two phosphorus-containing products were observed, in comparable amounts: ethyl phosphate, as observed on alkaline hydrolysis (chemical shift at 5.47 ppm), and a new signal at δ 31 P 3.68, assigned to EtO-PO 2 --ONH 2 6. The chemical shift assigned to 6 is consistent (deshielding by the 2,4-dinitrophenyl ring a typical 6 ppm) with the value of -2.04 ppm assigned to the product 2,4-dinitrophenyl-O-PO 2 --ONH 2 obtained from the similar reaction of hydroxylamine with bis(2,4-dinitrophenyl) phosphate by Domingos et al; 19 and with the value of δ = 6.5 found for the zwitterion HO-PO 2 --ONH 3 + by Weiss et al 20 (Chemical shifts from the literature have been corrected where necessary to refer to 85% phosphoric acid.) Table 5.…”

Organophosphorus Chemistry

“…17 The first catalytic methodology to convert glycals (41) into glycosyl phosphates (42) employing safe, commercially available reagents has been presented (Scheme 8). Examples include the synthesis of the enantiomers D-and L-myoinositol 1,3,4,6-tetrakisphosphate (45) and (46) regioisomers of myo-inositol 1,3,4,5-tetrakisphosphate. The synthesis consists of reactions of readily available S-(O,O-dialkyl)phosphorodithioates (44) or monothioates at various positions in the carbohydrate ring with fluoride anions.…”

In silico study on the mechanism of formation of hydrazine and nitrogen in the reactions of excess hydroxylamine with 2,4-dinitrophenyl diethyl phosphate

“…7 The unique property of hydroxylamine is that the nitrogen is alkylated and acylated, however, in general phosphorylated on oxygen with reaction through the oxygen atom. [8][9][10] The a-effect is known to enhance the reactivity with a lone pair of electrons on the atom adjacent to the nucleophilic centre. 11,12 These nucleophiles are of special interest due to their high reactivity toward phosphorus, making them suitable reagents of choice for the destruction of nerve gases and other organophosphorus poisons.…”