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.     

Carbon nucleophiles in the Mitsunobu reaction. Mono- and dialkylation of bis(2,2,2-trifluoroethyl) malonates

[formula: see text] Simple dialkyl malonate esters, for example diethyl malonate, exhibit relatively limited scope as carbon nucleophiles in the Mitsunobu dehydrative alkylation reaction. In contrast, bis(2,2,2-trifluoroethyl) malonate readily undergoes dehydrative alkylation with primary alcohols, and using only a slight excess of malonate gives monoalkylated product in good yield. Some secondary alcohols can also be employed, and bis(2,2,2-trifluoroethyl) malonates can be used in a second dehydrative alkylation to give dialkylated products in good to excellent yield.     

负载锌催化剂的缩合反应性能的研究

考察了由浸渍法制得的Zn2 + /AC ,Ni2 + /AC ,H+ /AC ,H+ +K+ /AC ,K+ /AC等催化剂存在下 ,由丙二酸二乙酯 (MDE)与原甲酸三乙酯 (OFE)在及少量乙酸或乙酸酐做缩合介质合成乙氧亚甲基丙二酸二乙酯 (EMME) .获得合成EMME较佳工艺条件 :用活性白土作为载体 ,负载 5 %Zn作为催化剂 ,催化剂用量为加入原料MDE的0 .3% (w) ,催化剂具有一定的重复使用性 ,EMME的收率可达到 98% (以MDE计 )     

Solid-Liquid Phase Transfer Catalytic Synthesis XII

The anion derived from diethyl malonate reacts with a series of halides readly under microwave irradiation, and the isolated yield of alkylated products varying from 64% to 86%.     

A Lewis acid-promoted cyclization of ethenetricarboxylate derivative aromatic compounds. Novel syntheses of oxindoles and benzofuranones via Friedel-Crafts intramolecular Michael addition

A novel cyclization reaction of ethenetricarboxylate derivative aromatic compounds in the presence of various Lewis acids gave benzo-annulated cyclic compounds such as oxindole and benzofuran derivatives via Friedel-Crafts intramolecular Michael addition in high yields. For example, the reaction of diethyl 2-[(N-methyl-N-phenylcarbamoyl)methylene]malonate (1a) in the presence of ZnCl2 at room temperature gave diethyl 2-(1-methyl-2-oxoindolin-3-yl)malonate (2a) in 98% yield. The reactions also proceeded with a catalytic amount of a Lewis acid such as AlCl3, ZnCl2, ZnBr2, Sc(OTf)3, or InBr3.     

A facile one step synthesis of novel ethyl 2,6-bis(trifluoromethyl)-4-hydroxypyrimidine-5-carboxylate

Trifluoroacetonitrile was condensed with diethyl malonate to give a novel ethyl 2,6-bis(trifluoromethyl)-4-hydroxypyrimidine-5-carboxylate ( 2 ) in 88% yield. Derivations of 2 are also described.     

(1-萘甲基)四氢糠基丙二酸二乙酯的新法合成

（１－萘甲基）四氢糠基丙二酸二乙酯（Ⅴ）是合成萘呋胺酯草酸盐的重要前体,而萘呋胺酯草酸盐作为一种新型周围血管扩张剂,正受到越来越多的重视［１,２］．（１－萘甲基）四氢糠基丙二酸二乙酯（Ⅴ）的原有合成方法［３］产率低,且反应时间长．本文改进了（Ⅴ）的原...     

Reaction of <Emphasis Type="Italic">N</Emphasis>-chloroamines with carbanions derived from ethyl acetoacetate and diethyl malonate

Carbanions derived from ethyl 3-oxobutanoate and diethyl malonate reacted with an equimolar amount of N-chloro-N-ethylethanamine, N-chloromorpholine, or N-chloropiperidine to give diethyl 2,3-diacetylbutanedioate and tetraethyl ethane-1,1,2,2-tetracarboxylate in 68–83% yield. The possibility of heterocoupling of ethyl 3-oxobutanoate and diethyl malonate carbanions by the action of N-chloro-N-ethylethanamine and the effect of the molar reactant ratio on the selectivity of oxidative homo- and heterocoupling were studied.     

4-烷基双环磷酸酯的合成研究

双环磷酸酯,即2,6,7-三氧杂-1-磷杂双环[2.2.2]辛烷1-氧化物的同系物,是哺乳动物的惊厥剂。惊厥活性产生于双环磷酸酯抑制神经递质 GABA 生理效应,是 GABA 的重要拮抗剂。这类化合物具有简单的刚性笼形结构,化学稳定性好,可作为有效的工具药。在各种类型双环磷酸酯的衍生物中,结构     

Synthesis of organostannyl barbiturates

(a) The synthesis of 2,4,6-trioxo-1, 3-di-tributylstannyl-hexahydropyrimidine is described. (b) Trimethyltin hydride is found to add in a photochemical reaction to the terminal double bond of diethyl allyl malonate and allyl methyl malonate, giving respectively diethyl-(3-trimethylstannylpropyl)- ( 1 ) and diethyl-(3-trimethylstannylpropyl) ( 2 ) methyl-malonates. Treated with urea under the usual conditions, ( 1 ) and ( 2 ) yield organostannyl barbituric acids.     

固液相烃基化反应的研究 I.以碳酸钾为碱的丙二酸乙二酯和氰乙酸乙酯的烃基化反应

The alkylation of diethyl malonate and ethyl cyanoacetate using powdered potassium carbonate asa base in the absence of solvent and other catalyst is studied. The features of this method are: simple preparative procedure, reproducible yield and easy control of monoalkylation. The reaction mechanism is discussed briefly.     

A New Application of Dimethyl Trithiocarbonate. Methylthiothiocarbonylation of 2,4-Pentanedione and Some β-Oxoesters

2,4-Pentanedione, ethyl acetoacetate, benzoyl acetate and diethyl malonate 1a-d react with sodium acetate and dimethyl trithiocarbonate in dimethylformamide to afford methyl-β,β′-dicarbonyldithiocarboxylate derivatives 2a-d in moderate yield.     

2-氨基-4,6-二氯-5-甲酰氨基嘧啶的合成

以丙二酸二乙酯和盐酸胍为起始原料,经环合、亚硝化、还原、氯化、水解得到2-氨基4,6-二氯-5-甲酰氨基嘧啶,总收率20％,其结构经61HNMR和IR表征。     

法西多曲原料药的合成

以胡椒醛和丙二酸酯为原料,经Knoevenagel缩合、常压催化氢化、缩合、加成、酰化5步反应合成了法西多曲,其结构经元素分析、IR和1H NMR表征。总收率72．1％。     

PEG-400介质中L-脯氨酸催化香豆素-3-羧酸乙酯的合成

用PEG-400为溶剂,L-脯氨酸作为催化剂,能高效简便地催化水杨醛与丙二酸二乙酯通过Knoevenagel缩合反应得到香豆素3-羧酸乙酯.本方法具有易于操作,后处理方便,反应时间较短,反应收率较高,催化剂和溶剂价廉易得,而且环境友好等优点.     

New Total Synthesis of O‐Methyledgeworin and Edgeworin

Upon thermal condensation of diethyl (coumarinyl‐7‐oxy)malonate with O‐methyl‐resorcine, the corresponding bis[coumarinyl]ether, 4‐hydroxy‐O‐methyledgeworin is obtained in good yield. This leads to 4‐bromo‐O‐methyledgeworin, O‐methyledgeworin, and edgeworin.     

Mechanism of electrodimerization of retinal and cinnamaldehyde

Electrochemical reduction of either cinnamaldehyde or retinal in acetonitrile containing 0.5 M. TBAP and water or phenol leads to a mixture of dimeric products. However, electroreduction of either of these aldehydes in the presence of the carbon acid, diethyl malonate, leads to increased yield of pinacol formation. The mechanism of these electrodimerization reactions has been discerned using cyclic voltammetry-variations in peak potential as a function of scan rate, proton donor concentration and concentration of aldehyde have been compared to published diagnostic criteria. Retinal and cinnamaldehyde form dimeric products in a radical-radical coupling pathway. The major mechanistic feature that correlates with product distribution is the association (solvation) of oxygen acids, phenol and water with the radical anion. In contrast, diethyl malonate reacts with the radical anion of either cinnamaldehyde or retinal by a direct proton transfer.     

A Facile One-Step Synthesis of Ethyl 2-(L,L-Dialkyl and Arylmethyl) Malonates

Diethyl ethoxymethylenemalonate (EMME) is unexpectedly converted into diethyl 2-(1,1 -dialkyl and diarylmethyl) malonate derivatives by a classical Grignard reaction. Addition of organocuprates to EMME gave diethyl 2-(l-ethoxyalkyl) malonate derivatives. The yields range from 42-63%.     

Some interesting CH_2CH_3 spin systems in several diethyl malonate indene derivatives studied with NMR and molecular modeling

While studying the electrophilic cyclization of acetylenic malonates in synthesizing malonate indene derivatives with high regio and stereo-selectivity, we found that the CH2 and CH3 protons of two COOCH2CH3 groups in some diethyl malonate indene derivatives showed very interesting spin-spin coupling and signal multiplicity. To explain those phenomena, we synthesized several diethyl malonate indene derivatives, and then used 1H NMR spectra and molecular modeling to investigate the CH2CH3 spin system of thes...     

邻氰基-D，L-苯丙氨酸盐酸盐的合成与表征

氨基酸是构成多肽的基本单位,肽链中不同的氨基酸及氨基酸所含基团的不同使其在化学和生物活性等方面有着不同的性质。通过改变肽链中不同氨基酸来修饰肽链的结构和环境,能赋子肽链新的功能。天然氨基酸由于结构的原因,无法满足特殊的需要。随着生物化学合成、分离和测试技术的