113947-93-6Relevant articles and documents
Mechanistic insight on the catalytic detoxification of Paraoxon mediated by imidazole: Furnishing optimum scaffolds for scavenging organophosphorus agents
Orth, Elisa S.,Almeida, Thomas Golin,Silva, Valmir B.,Oliveira, Alfredo R.M.,Ocampos, Fernanda Maria Marins,Barison, Andersson
, p. 93 - 98 (2015)
Any agricultural growth concomitantly increases the demand for pesticides and there is a major concern in monitoring these agents, in order to identify their indiscriminate use, avoid contamination and also to detect prohibited species. Organophosphorus c
Transfer of the Diethoxyphosphoryl Group between Imidazole and Aryloxy Anion Nucleophiles
Ba-Saif, Salem,Williams, Andrew
, p. 2204 - 2209 (2007/10/02)
Rate constans have been measured for reaction of imidazole with aryl diethyl phosphate (k1) and of aryloxy anions with N-(diethoxyphosphoryl)imidazolium ion (k-1) in aqueous solution at 25 deg C; they obey the following linear Broensted equations: log k1 = -1.02pKArOH + 1.83 (n = 6, r = 0.989); log k-1 = 0.85pKArOH - 0.48 (n = 10, r = 0.957).The value of βeq (1.87) obtained from βlg and βnuc supports a previously determined value (1.83) for the transfer of the neutral phosphoryl group from phenolate ion nucleophiles.The pKaof (diethoxyphosphoryl)imidazolium ion is 6.04.The equilibrium constant for reaction of 4-nitrophenyl diethyl phosphate with imidazole is 5.9 x 10-6; in the case of the aryl ester from phenol with pKArOH = 4.34 the equilibrium constant is calculated to be unity.The Broensted βeq data are used to calibrate effective charges derived from previously measured βlg values for attack of nucleophiles at phosphorus bearing phenolate ion leaving groups.
31P NMR Study of the Mechanism of Activation and Coupling Reactions in the Synthesis of Oligodeoxyribonucleotides by the Phosphotriester Method
Chandrasegaran, Srinivasan,Murakami, Akira,Kan, Lou-sing
, p. 4951 - 4957 (2007/10/02)
The phosphotriester method provides a rapid and convenient procedure for synthesizing oligonucleotides.The mechanism has been revealed and intermediates have been identified by 31P NMR methodology.It was found that reaction of a 5'-protected nucleoside 3'-(p-chlorophenyl phosphate) with mesitylenesulfonyl chloride (MSCl) or 1-(mesitylyl-2-sulfonyl)-3-nitro-1,2,4-triazole (MSNT) in anhydrous pyridine yields only two products within 5 min, the sulfonic acid-phosphate mixed anhydride 2 and the (3'-3') symmetrical pyrophosphate tetraester 3 which can be isolated as a mixture.Reaction of 2 and 3 with 3'-O-acetylthymidine yields the phosphotriester dimer NpTOAc.The reaction rate and yield of dimers are closely dependent on the presence of catalysts.The reaction finished within minutes when tetrazole or 3-nitro-1,2,4-triazole was used.On the contrary, the reaction completed in hours when imidazole or 1,2,4-triazole was used as catalysts.The possible mechanisms are explored and discussed in detail.
