A FACILE SYNTHESIS OF DIETHYL 1- ISOTHIOCYANO)ALKYLPHOSPHONATES[1]

Abstract

Novel, diethyl 1-(isothiocyano)alkylphosphonates 3 have been efficiently synthesized via a one-pot reaction of diethyl 1-azidoalkylphosphonates 1 with triphenylphosphine, followed by in situ transformation of thus formed phosphazenes 2 with carbon disulfide. Application of the title compounds in the synthesis of diethyl (N-phenylthioureido)- and (benzothiazol-2-ylamino)methylphosphonates was also described.     

Reactions of 1,2-ethanedithiol and 2-mercaptoethanol with unsaturated derivatives of four-coordinate phosphorus acids

The reaction of 1,2-ethanedithiol with diethyl vinylphosphonate in the presence of EtONa occurs as the addition of the sulfhydryl group to the β-carbon atom of the substrate to give 1 : 1 and 1 : 2 adducts. The nucleophilic addition of 2-mercaptoethanol at the β position of the multiple bond of diethyl vinyl-, diethyl allenyl-, and diethyl prop-1-ynylphosphonates involves only the sulfhydryl group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2156–2159, October, 2004.     

Thermal behaviour of covalently bonded phosphate and phosphonate flame retardant polystyrene systems

Pyrolyses of the reactively flame retarded polystyrene copolymers styrene/diethyl(acryloyloxyethyl)phosphate(S/DEAEP), styrene/diethyl(methacryloyloxyethyl)phosphate(S/DEMEP), styrene/diethyl(methacryloyloxymethyl)phosphonate(S/DEMMP) and styrene/diethyl(acryloyloxymethyl)phosphonate(S/DEAMP) have been investigated with a view to obtaining information pertinent to the mechanism of their flame retardant behaviour. Studies were also carried out on the additive polystyrene systems containing triethylphosphate (TEP) and diethylethylphosphonate (DEEP) for comparison. All the systems contained 3.5 wt% of phosphorus. A range of techniques were used, namely TG with EGA, DSC, SEM, laser and microfurnace pyrolysis mass spectrometry and isothermal pyrolysis/GC-MS, to study the decompositions under a range of conditions. In the case of the additive systems, the additive was shown to be evolved before polymer decomposition occurred. Very little, if any, char residues were observed. Thus the main mechanism of fire retardant action of the phosphorus incorporated into the polystyrene as an additive would occur in the vapour phase. This mechanism prevailed regardless of whether the additive was a phosphate (TEP) or a phosphonate (DEEP). The effectiveness of the fire retardant action would be limited as the fire retardant and fuel did not volatilise together. There was evidence that some interaction occurred in the condensed phase. In all the copolymers the phosphorus content of the char was substantial. This is characteristic of the condensed phase fire retardant action of phosphorus. SEM studies showed the interior of the char to be a network of channels which would give the char a sponge-like interior which would enhance thermal insulation. The surfaces were relatively dense thus providing a barrier to escape for any gaseous products formed in the interior. Char formation and cross-linking are assumed to be the result of the presence of the strong phosphoric and phosphonic acids resulting from initial pyrolysis. Since phosphonic is the weaker acid, the polymer degradation and release of volatile products may be less inhibited in the case of the phosphonate-containing copolymers compared to the phosphate-containing copolymers. This is consistent with their shorter times to ignition. There was also evidence for some potential phosphorus vapour phase fire retardant action as phosphorus-containing species were identified among the pyrolysis products for all samples. The rate of volatile evolution from the copolymers was reduced compared to that of the corresponding additive system.     

N,N-二(2-羟乙基)氨甲基膦酸二乙酯的合成

改进了非卤反应型阻燃剂N,N-二(2-羟基乙基)氨甲基膦酸二乙酯(BHAPE)的合成方法.在35℃左右将二乙醇胺滴入37%~40%的甲醛水溶液中,加毕,于40~45℃继续保温反应2 h,然后于80~82℃,小于0.094 MPa,减压蒸馏直到没有馏分为止,得到中间体3-(2-羟基乙基)-1,3-氧氮杂环戊烷(HENH).向HENH中加入阳离子交换树脂催化剂,于55~62℃滴入亚磷酸二乙酯,加毕,于60~62℃保温反应2 h,降到室温,过滤回收催化剂,得黄色透明液体产品,收率98.5%.用元素分析、红外光谱和核磁共振谱表征了中间体和标题化合物.     

A concise synthesis of protected diethyl 1-amino-2-hydroxyalkylphosphonates

An efficient diastereoselective synthesis of 5-substituted (2-thioxo-oxazolidin-4-yl)phosphonic acid diethyl esters from metallated diethyl isothiocyanomethylphosphonate and aldehydes has been developed. The three-step transformation of oxazolidine-2-thione derivatives into N-Boc 1-amino-2-hydroxyalkylphosphonic acid diethyl esters is also described.     

二羟基丙酮磷酸酯的合成

本文报道由3-氯-1,2-丙二醇(1)经七步反应,合成二羟基丙酮磷酸酯缩乙酮(7)的方法,总收率43%。在温和条件下,7可以水解为游离的二羟基丙酮磷酸酯(8)。     

固相萃取/高效液相色谱-串联质谱法同时检测多类食品中二甲基黄、二乙基黄含量

建立了豆干、辣椒酱、豆腐乳、腐竹和饼干等样品中二甲基黄和二乙基黄残留量的液相色谱-串联质谱分析方法。基于二甲基黄和二乙基黄的化学结构特性,采用乙腈溶液提取。提取液酸化后经Bond Elut Plexa PCX阳离子交换树脂固相萃取净化,吹干复溶后,使用反相C_(18)色谱柱分离,电喷雾串联四极杆质谱正离子化多反应监测(MRM)模式检测。二甲基黄和二乙基黄的方法定量下限均为0.50μg/kg。对5种不同基质样品进行二甲基黄和二乙基黄0.50,5.0,80μg/kg 3个浓度水平的加标回收实验,得到二甲基黄和二乙基黄的平均回收率分别为76.4%~93.0%和76.1%~92.4%;相对标准偏差分别为1.7%~6.3%和1.9%~7.4%,可以满足食品中二甲基黄和二乙基黄快速筛查和定量分析的要求。     

Two new polyketides isolated from a diethyl sulphate mutant of marine-derived Penicillium purpurogenum G59

Two new polyketides, purpurofuranone (1) and purpuropyranone (2), were isolated along with the known polyketides, cillifuranone (3) and taiwapyrone (4), from a mutant BD-3n-1 derived from the diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. The structures of 1 and 2 were elucidated by spectroscopic methods especially on the basis of X-ray diffraction and calculated optical rotations data. The plausible biosynthesis of 1???4 was also proposed and discussed. In preliminary MTT assay, 1???4 showed no notable inhibitory effects on the tested four human cancer cell lines.     

1,3-Dipolar addition of diethyl diazomethylphosphonate onto a CN double bond. Synthesis of triazolinyl and aziridinyl phosphonates

Cycloaddition of diethyl 1-diazomethylphosphonate onto a CN double bond is described. It was found that the reaction of this phosphorus diazomethane with benzylidene-alkyl-amines resulted in the formation of (1-alkyl-5-phenyl-4,5-dihydro-1H-[1,2,3]triazol-4-yl)-phosphonic acid diethyl esters, whereas its reaction with methylene-aryl-amines, generated from the corresponding hexahydro-1,3,5-triazines, led to diethyl esters of (aziridin-2-yl)-phosphonic acid.     

PREPARATION OF DIETHYL 1-BROMOALKYLPHOSPHONATES

Abstract

Diethyl 1-bromoalkylphosphonates 1 have been obtained in good to moderate yields by the reaction of diethyl I-hydroxyalkylphosphonates 2 with the triphenylphosphine-carbon tetrabromide system or dibromotriphenylphosphorane.     

Three-Component,One-Pot Synthesis of New Functionalized Pyrrolines

The addition of acetylenic esters to diethyl acetamidomalonate in the presence of tert-butyl isocyanide leads to highly functionalized 1-pyrrolines and 2-pyrroline.     

The thermal degradation of poly(diethyl fumarate)

The kinetics and mechanism of the thermal degradation of poly(diethyl fumarate) (PDEF) were studied by thermogravimetry, as well as by analysis of the thermolysis volatiles and polymer residue. The characteristic mass loss temperatures were determined, as were the overall thermal degradation activation energies of three PDEF samples of varying molar mass. Ethylene and ethanol were present in the thermolysis volatiles at degradation temperatures below 300 °C, while diethyl fumarate was also evidenced at higher degradation temperatures. The amount of monomer increased with increasing degradation temperature. The dependence of the molar mass of the residual polymer on the degradation time and temperature was established and the number of main-chain scissions per monomer unit, s/P₀, calculated. A thermal degradation mechanism including de-esterification and random main-chain scission is proposed. The thermal degradation of PDEF was compared to the thermolysis of poly(ethyl methacrylate) (PEMA), poly(diethyl itaconate) (PDEI) and poly(ethyl acrylate) (PEA).     

An efficient method for the preparation of mono α-aryl derivatives of diethyl malonate and ethyl cyanoacetate using ethyl-1-imidazole carbamate (EImC)

An efficient method for the synthesis of mono α-aryl derivatives of diethyl malonate and ethyl cyanoacetate using ethyl-1-imidazole carbamate (EImC) has been described. Using this method many sterically hindered and highly substituted mono α-aryl derivatives of diethyl malonate and ethyl cyanoacetate were synthesized in high yield.     

Reactions of 1,3-bis(ω-bromoalkyl)-6-methyluracils with 2-(dialkylamino)ethylphosphonates and 2-(dialkylamino)ethyl phosphates

1,3-Bis(4-bromobutyl)-6-methyluracil reacts with diethyl 2-(dimethylamino)ethylphosphonate to form a bisquaternary ammonium salt, whereas the reaction of 1,3-bis-(6-bromohexyl)-6-methyluracil with diethyl 2-(diethylamino)ethyl phosphate gives 1,3-bis-[(6-diethoxyphosphoryloxy)hexyl]-6-methyluracil and 1,1,4,4-tetraethylpiperazinium dibromide. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1130–1132, June, 2000.     

甲醇-三氟化硼乙醚混合质子电解质

甲醇和三氟化硼乙醚(BFEE)本身离子电导率很低,向甲醇溶液中加入少量BFEE可以形成良好的质子电解质溶液.随着甲醇中BFEE浓度的变化,溶液的离子电导率具有最大值,达20mS/cm.红外光谱和1HNMR研究表明混合电解质中的主要导电离子为MeOH2+和MeOBF3-.     

手性流动相添加剂法拆分西那卡塞原料及中间体

以自制1-萘万古霉素(Na-VAN)为手性固定相(CSP),D-酒石酸(D-Tar)、L-酒石酸二乙酯(L-TADE)、D-酒石酸二乙酯(D-TADE)分别为手性流动相添加剂(CMPA),建立了西那卡塞原料1-(1-萘基)乙胺(化合物1)及西那卡塞中间体(化合物2)的高效液相色谱手性拆分方法。考察了流动相中醇类改性剂、CMPA对对映体分离的影响,初步探讨了手性识别机理。以Na-VAN为CSP,正相模式下,添加不同种类的CMPA,化合物1、化合物2均可获得一定程度的分离,其中以D-TADE为CMPA时,化合物1、化合物2获得最佳分离。结果表明,醇的分子体积、CMPA的立体构型均对手性分离有影响。     

A Double-Site Chemodosimeter for Selective Fluorescence Detection of a Nerve Agent Mimic

A novel two-site chemodosimeter (SWJT-4) based on fluorescein skeleton to detect diethyl chlorophosphate (DCP) was designed and synthesized. It is a turn-on fluorescent probe for DCP with good selectivity and obvious color change in aqueous solution. Interestingly, the two oxime groups of SWJT-4 as dual response sites initiated different reactions with DCP to form a cyano group and an isoxazole ring, respectively. The corresponding mechanism was confirmed by ¹H NMR, MS and DFT calculation. Moreover, SWJT-4 could be used as a fluorescent test paper to detect DCP vapor.     

Alternatives to N,N‐Diethyl‐2,4‐dimethoxybenzamide as a Precursor for the Synthesis of 6,8‐Dimethoxy‐3‐methyl‐3,4‐dihydro‐1H‐isochromen‐1‐one

Although the amide group of N,N‐diethyl‐2,4‐dimethoxybenzamide facilitates directed ortho‐metallation and subsequent allylation of the aromatic ring, it is not readily hydrolyzed prior to conversion into the title isochromenone. This article describes the use of 1‐(2‐allyl‐4,5‐dimethoxybenzoyl)‐4‐methylpiperazine and N,N‐diethyl‐2‐(2‐hydroxypropyl)‐4,6‐dimethoxybenzamide as alternative substrates for conversion into 6,8‐dimethoxy‐3‐methyl‐3,4‐dihydro‐1H‐isochromen‐1‐one.     

磷酸硼固体酸催化合成邻苯二甲酸二乙酯的性能研究

以邻苯二甲酸酐和无水乙醇为原料,固体磷酸硼为催化剂,在醇酐比为4：1,催化剂用量为苯酐用量的20．3％,反应时间8h,反应温度80℃条件下合成邻苯二甲酸二乙酯（DEP）,探讨了影响催化剂催化效果的各个因素。实验表明,催化剂最佳的制备条件为：磷酸、硼酸和硫酸的摩尔比为1：1：1,焙烧温度为300℃,焙烧时间为3．5h。DEP最高产率可达75％。     

Atmospheric pressure chemical vapour deposition of selenium and tellurium films by UV laser photolysis of diethyl selenium and diethyl tellurium

Excimer laser‐induced photolysis of gaseous diethyl selenium and diethyl tellurium (C₂H₅)₂M (M = Se, Te) is controlled by cleavage of both M? C bonds, it yields C₁–C₄ hydrocarbons (ethene as major product) and results in chemical vapour deposition of selenium films and nanosized tellurium powder. The selenium and tellurium properties were characterized by X‐ray photoelectron spectroscopy and Scanning electron Microscopy techniques. Copyright © 2001 John Wiley & Sons, Ltd.