Organophosphorus compounds. P-Arylated perhydro-1,2-azaphosphorines

1977 ◽  
Vol 30 (3) ◽  
pp. 579 ◽  
Author(s):  
DG Hewitt ◽  
GL Newland
Keyword(s):  
Thionyl Chloride ◽  
Good Yield ◽  
Aqueous Ammonia ◽  
Organophosphorus Compounds ◽  
Phosphinic Acid ◽  
Sodium Hydride ◽  
Hydrolysis Of ◽  
Phenylmagnesium Bromide

Treatment of ethyl 4-bromobutylphosphonochloridate with phenylmagnesium bromide, followed by acid-catalysed hydrolysis of the product, gave 4- bromobutyl(phenyl)phosphinic acid. This was converted into the corresponding phosphinamide by treatment with thionyl chloride and then with aqueous ammonia. Cyclodehydrobromination with sodium hydride in warm xylene then gave a good yield of 2-phenylperhydro-1,2- azaphosphorine 2-oxide. Some other routes to this compound were investigated.

Organophosphorus compounds. XIX. Synthesis of 2,3-Dihydro-1 H-1,2-benzazaphosphole 2-oxides, variously substituted on nitrogen and phosphorus, by N-P cyclization of zwitterionic intermediates

1983 ◽  
Vol 36 (12) ◽  
pp. 2517 ◽  
Author(s):  
DJ Collins ◽  
PF Drygala ◽  
JM Swan
Keyword(s):  
Ethyl Ester ◽  
Organophosphorus Compounds ◽  
Phosphinic Acid ◽  
Nitrogen And Phosphorus ◽  
Hydrochloride Salt ◽  
Analogous Manner ◽  
Conventional Methods ◽  
Hydrolysis Of

2-Phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-oxide (7a) was prepared by thermolysis of the corresponding zwitterionic amino phosphinic acid (4), or its hydrochloride salt (1). Thermolysis of methyl (2-aminobenzy1)phenylphosphinate (5a) was accompanied by intermolecular O→N transmethylation to give, after cyclization, l-methyl-2-phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-oxide (9a); similarly, the ethyl ester (5b) gave the N-ethyl heterocycle (9b). Reaction of 2-phthalimidobenzyl bromide (13a) with diethyl methylphosphonite (14b) gave ethyl (2-phthalimidobenzy1)methylphosphinate (15a). Hydrolysis of (15a) afforded (2-aminobenzyl)- methylphosphinic acid (16), and thermolysis of this produced 2-methyl-2,3-dihydro-lH-1,2-benzaza- phosphole 2-oxide (18a). 1-Methyi-2-methoxy-2,3-dihydro-1H-l,2-benzazaphosphole 2-oxide (24) was synthesized in an analogous manner. Base catalysed N-alkylation of the benzazaphosphole derivatives (7a) and (18a) was readily achieved, and the interconversion of 2-oxides and 2-sulfides was accomplished by conventional methods.

scholarly journals MW irradiation and ionic liquids as green tools in hydrolyses and alcoholyses

2020 ◽  
Vol 10 (1) ◽  
pp. 001-010 ◽  
Author(s):  
Nikoletta Harsági ◽  
Betti Szőllősi ◽  
Nóra Zsuzsa Kiss ◽  
György Keglevich
Keyword(s):  
Ionic Liquids ◽  
Alkaline Hydrolysis ◽  
Alkyl Group ◽  
Phosphinic Acid ◽  
Reaction Times ◽  
Alternative Possibility ◽  
First Order ◽  
Pseudo First Order ◽  
Mw Irradiation ◽  
Hydrolysis Of

Abstract The optimized HCl-catalyzed hydrolysis of alkyl diphenylphosphinates is described. The reaction times and pseudo-first-order rate constants suggested the iPr > Me > Et ∼ Pr ∼ Bu order of reactivity in respect of the alkyl group of the phosphinates. The MW-assisted p-toluenesulfonic acid (PTSA)-catalyzed variation means a better alternative possibility due to the shorter reaction times, and the alkaline hydrolysis is another option. The transesterification of alkyl diphenylphosphinates took place only in the presence of suitable ionic liquids, such as butyl-methylimidazolium hexafluorophosphorate ([bmim][PF6]) and butyl-methylimidazolium tetrafluoroborate ([bmim][BF4]). The application of ethyl-methylimidazolium hydrosulfate ([emim][HSO4]) and butyl-methylimidazolium chloride ([bmim][Cl]) was not too efficient, as the formation of the ester was accompanied by the fission of the O–C bond resulting in the formation of Ph2P(O)OH. This surprising transformation may be utilized in the phosphinate → phosphinic acid conversion.

scholarly journals Simultaneous Hydrolysis and Detection of Organophosphate by Benzimidazole Containing Ligand-Based Zinc(II) Complexes

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 714
Author(s):  
Gaber A. M. Mersal ◽  
Hamdy S. El-Sheshtawy ◽  
Mohammed A. Amin ◽  
Nasser Y. Mostafa ◽  
Amine Mezni ◽  
...  
Keyword(s):  
Square Wave Voltammetry ◽  
Limit Of Detection ◽  
Organophosphorus Compounds ◽  
Organophosphorus Pesticides ◽  
Carbon Paste ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Carbon Past Electrode ◽  
Hydrolysis Of ◽  
Biomimetic Sensor

The agricultural use of organophosphorus pesticides is a widespread practice with significant advantages in crop health and product yield. An undesirable consequence is the contamination of soil and groundwater by these neurotoxins resulting from over application and run-off. Here, we design and synthesize the mononuclear zinc(II) complexes, namely, [Zn(AMB)2Cl](ClO4) 1 and [Zn(AMB)2(OH)](ClO4) 2 (AMB = 2-aminomethylbenzimidazole), as artificial catalysts inspired by phosphotriesterase (PTE) for the hydrolysis of organophosphorus compounds (OPs) and simultaneously detect the organophosphate pesticides such as fenitrothion and parathion. Spectral and DFT (B3LYP/Lanl2DZ) calculations revealed that complexes 1 and 2 have a square-pyramidal environment around zinc(II) centers with coordination chromophores of ZnN4Cl and ZnN4O, respectively. Both 1 and 2 were used as a modifier in the construction of a biomimetic sensor for the determination of toxic OPs, fenitrothion and parathion, in phosphate buffer by square wave voltammetry. The hydrolysis of OPs using 1 or 2 generates p-nitrophenol, which is subsequently oxidized at the surface of the modified carbon past electrode. The catalytic activity of 2 was higher than 1, which is attributed to the higher electronegativity of the former. The oxidation peak potentials of p-nitrophenol were obtained at +0.97 V (vs. Ag/AgCl) using cyclic voltammetry (CV) and +0.88 V (vs. Ag/AgCl) using square wave voltammetry. Several parameters were investigated to evaluate the performance of the biomimetic sensor obtained after the incorporation of zinc(II) complex 1 and 2 on a carbon paste electrode (CPE). The calibration curve showed a linear response ranging between 1.0 μM (0.29 ppm) and 5.5 μM (1.6 ppm) for fenitrothion and 1.0 μM (0.28 ppm) and 0.1 μM (0.028 ppm) for parathion with a limit of detection (LOD) of 0.08 μM (0.022 ppm) and 0.51 μM (0.149 ppm) for fenitrothion and parathion, respectively. The obtained results clearly demonstrated that the CPE modified by 1 and 2 has a remarkable electrocatalytic activity towards the hydrolysis of OPs under optimal conditions.

scholarly journals Synthesis and Antimicrobial Activities of Some New Thieno and Furopyrimidine Derivatives

2009 ◽  
Vol 1 (2) ◽  
pp. 317-325 ◽  
Author(s):  
M. I. Hossain ◽  
M. M. H. Bhuiyan
Keyword(s):  
Antimicrobial Activity ◽  
Formic Acid ◽  
Hydrazine Hydrate ◽  
Thionyl Chloride ◽  
Good Yield ◽  
Initial Treatment ◽  
Antimicrobial Activities

Fused pyrimidines, 8,9-dimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 5, 3,8,9-trimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 6, 4-benzylidinehydrazono-5,6  dimethylthieno[2,3-d]pyrimidine 7, 4-[4/-hydroxybenzylidine]hydrazono-5,6-dimethylthi-eno[2,3-d]pyrimidine 8, 4-[4/-tolylidin]hydrazono-5,6-dimethylthieno[2,3-d]pyrimidine 9, 4-[4/-nitrobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 10 and 4-[4/-chlorobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 11 are prepared in good yield by an initial treatment of 2-amino-4,5-dimethylthiophene-3-carbonitrile 1 with formic acid, affording 5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-one 2, which is chlorinated with thionyl chloride and then hydrazinated with hydrazine hydrate. Finally hydrazino compound 4 is reacted with formic acid, acetic anhydrate, benzaldehyde, p-hydroxybenzaldehyde, p-toluayldehyde, p-nitrobenzaldehyde and p-chlorobenzaldehyde to give thienotriazolopyrimidines 5-6 and thienopyrimidines 7-11 respectively. All the compounds have been screened for their antimicrobial activity. Keywords: Fused pyrimidines; Hydrazino compound; Thienotriazolopyrmidines; Thienopyrimidines; Antimicrobial activity.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2299

Improving the efficiency of enzymatic hydrolysis of Eucalyptus residues with a modified aqueous ammonia soaking method

2018 ◽  
Vol 33 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Dan Huo ◽  
Qiulin Yang ◽  
Guigan Fang ◽  
Qiujuan Liu ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Hydrolysis ◽  
Aqueous Ammonia ◽  
Pulp Mill ◽  
Fiber Surface ◽  
Raw Material ◽  
Sem Images ◽  
Aqueous Ammonia Soaking ◽  
Guaiacyl Lignin ◽  
Hydrolysis Of

Abstract Eucalyptus residues from pulp mill were pretreated with aqueous ammonia soaking (AAS) method to improve the efficiency of enzymatic hydrolysis. The optimized condition of AAS was obtained by response surface methodology. Meanwhile, hydrogen peroxide was introduced into the AAS system to modify the AAS pretreatment (AASP). The results showed that a fermentable sugar yield of 64.96 % was obtained when the eucalypt fibers were pretreated at the optimal conditions, with 80 % of ammonia (w/w) for 11 h and keeping the temperature at 90 °C. In further research it was found that the addition of H2O2 to the AAS could improve the pretreatment efficiency. The delignification rate and enzymatic digestibility were increased to 64.49 % and 73.85 %, respectively, with 5 % of hydrogen peroxide being used. FTIR analysis indicated that most syringyl and guaiacyl lignin and a trace amount of xylan were degraded and dissolved during the AAS and AASP pretreatments. The CrI of the raw material was increased after AAS and AASP pretreatments, which was attributed to the removal of amorphous portion. SEM images showed that microfibers were separated and explored from the initial fiber structure after AAS pretreatment, and the AASP method could improve the destructiveness of the fiber surface.

Stepwise pretreatment of aqueous ammonia and ethylenediamine improve enzymatic hydrolysis of corn stover

2018 ◽  
Vol 124 ◽  
pp. 201-208 ◽  
Author(s):  
Jia-Qing Zhu ◽  
Wen-Chao Li ◽  
Lei Qin ◽  
Xiong Zhao ◽  
Si Chen ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Aqueous Ammonia ◽  
Hydrolysis Of

Synthesis of Symmetrical Dipurine-Nucleoside Diphosphates from the Corresponding Nucleoside Phosphoropiperidates

2014 ◽  
Vol 1023 ◽  
pp. 55-58
Author(s):  
Xiao Chuan Li ◽  
Shan Shan Gong ◽  
Qi Sun
Keyword(s):  
Efficient Method ◽  
Good Yield ◽  
Purine Bases ◽  
Hydrolysis Of

A general and efficient method for the preparation of symmetrical dinucleoside diphosphates with purine bases has been developed. Ap2A and Gp2G were synthesized from the in situ hydrolysis of corresponding nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator. This method features easily accessible starting materials, simple procedures, and good yield.

Study and modeling of mechanisms of cholinesterasis reactions in order to improve their catalytic properties in the neutralization reactions of organophosphorous compounds

2020 ◽  
pp. 134-174
Author(s):  
Sergey Varfolomeev ◽  
Bella Grigorenko ◽  
Sofya Lushchekina ◽  
Patrick Masson ◽  
Galina Mahaeva ◽  
...  
Keyword(s):  
First Generation ◽  
Organophosphorus Compounds ◽  
Protein Molecule ◽  
Catalytic Antibodies ◽  
High Rate ◽  
Biological Targets ◽  
Organophosphorous Compounds ◽  
Rate Of Hydrolysis ◽  
The Stability ◽  
Hydrolysis Of

“Biocleaners” or “bioscavengers” are biological objects (enzymes, catalytic antibodies) that are capable of binding and/or hydrolyzing organophosphorus compounds (OPC). Their use seems to be the most effective alternative to traditional antidotes to neutralize or detoxify OPC. The introduction of bioscavengers allows neutralizing toxicant molecules in the bloodstream before they reach their biological targets, thereby providing protection against poisoning. Bioscavengers of the first-generation neutralized OPC molecules by stoichiometrically binding to them. The safety and efficacy of human butyrylcholinesterase (BChE) for protecting against OPC poisoning has been shown. However, the stoichiometric neutralization of OPC requires the introduction of a huge amount of expensive biopharmaceuticals. Catalytic bioscavengers that hydrolytically neutralize OPC were introduced at a much lower dose to achieve the same degree of effectiveness. The most effective catalytic bioscavengers are enzymes. The most promising enzymes are artificial mammalian paraoxonase mutants and bacterial phosphotriesterases. However, studies of other enzymes, such as prolidases, oxidases, artificial mutants of cholinesterases and carboxyl esterases and catalytic antibodies are actively ongoing. Since OPC are pseudosubstrates of cholinesterases (ChEs), a detailed description of the mechanisms of inhibition, dealkylation, and spontaneous reactivation of phosphorylated ChEs is critical for the development of ChEs mutants with a high rate of hydrolysis of OPC. The review presents an analysis of different views on the mechanisms of interaction of ChEs with OPC, discusses the possible directions of creating effective catalytic biological traps based on BChE and changes in their mechanism of action as compared to the native enzyme. A separate section is devoted to the effect of mutations, both polymorphic and artificial, on the stability of the protein molecule of BChE.

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