Malonates ethyl

Substitution Derivatives of Ethyl Malonate, Ethyl malonate resembles ethyl acetoacetate in that it gives rise to mono- and di-substituted derivatives in precisely similar circumstances. Thus when ethanolic solutions of ethyl malonate and of sodium ethoxide are mixed, the sodium derivative (A) of the enol form is produced in solution. On boiling this solution with an alkyl halide, e.g, methyl iodide, the methyl derivative (B) of the keto form is obtained. When this is treated again in ethanolic solution with sodium ethoxide, the... 

It is now applied more widely to include malonic acid derivatives, such as diethyl monoethyl-malonate, ethyl cyanacetate, etc. Various amines may be used as catalysts, and usually the most effective is piperidine (hexahydro-pyridine) a mixture of piperidine and pyridine, or pyridine alone, is also often used. 

The addition of active methylene compounds (ethyl malonate, ethyl aoeto-acetate, ethyl plienylacetate, nltromethane, acrylonitrile, etc.) to the aP-double bond of a conjugated unsaturated ketone, ester or nitrile In the presence of a basic catalyst (sodium ethoxide, piperidine, diethylamiiie, etc.) is known as the Michael reaction or Michael addition. The reaction may be illustrated by the addition of ethyl malonate to ethyl fumarate in the presence of sodium ethoxide hydrolysis and decarboxylation of the addendum (ethyl propane-1 1 2 3-tetracarboxylate) yields trlcarballylic acid ... 

Halogenopyrimidines react with active methylene groups, such as those in diethyl malonate, ethyl cyanoacetate, ketene diethylacetal, etc. For example, 4-chloro-6-methyl-5-nitropyrimidin-2-amine (454) and dimethyl sodiomalonate give dimethyl 2-amino-6-methyl-5-nitropyrimidin-4-ylmalonate (455) (63ZOB3132) 2-chloro-4,6-... 

Ethyl malonate, see Diethyl malonate Ethyl mercaptan, see Ethanethiol ... 

Diethyl oxalate functioned as one-carbon rather than two-carbon cyclizing agent with the diamino-heterocyclopyrimidines 37 to give the triazo-lopyrimidines 38. Diethyl malonate, ethyl acetoacetate, or ethyl... 

Ethyl Malonate.—Ethyl malonate is not a member of the parafiinoid acid esters, but is sufficiently nearly related to this series to be included here as a matter of convenience. It is of considerable value in modifying flower odours, having a more or less characteristic apple odour, but of a much sweeter type than the valerianic ester perfume. It is an oil of specific gravity 1 068, and boils at 198°. 

Chloroquinoxaline with diethyl malonate, ethyl cyanoacetate, or malononitrile gave 2-(diethoxycarbonylmethyl)- (57), 2-(a-cyano-a-ethoxycarbonylmethyl)-(58, R = COaEt), or 2-(dicyanomethyl)quinoxaline (58, R = CN) [KOH,... 

The monoethyl A -(6-methyl-2-pyridyl)aminomethylenemalonate was prepared in 34% yield in the reaction of monoethyl malonate, ethyl orthoformate, and 2-amino-6-methylpyridine in the presence of catalytic amounts of A1C13 at 110-115°C for 45 min (72AF815). 

Finally, Nikishin and coworkers have reported that the mediated oxidations of doubly activated methylene compounds can be used to synthesize cyclopropane derivatives (Scheme 17) [30]. Reactions using dimethyl malonate, ethyl cyanoacetate, and malononitrile were studied. Metal halides were used as mediators. When the activated methylene compound was oxidized in the absence of a carbonyl compound, three of the substrate molecules were coupled together to form the hexasubstituted product. Interestingly, when the ethyl cyanoacetate substrate was used the product was formed in a stereoselective fashion (18b). In an analogous reaction, oxidation of the activated methylene compounds in the presence of ketones and aldehydes led to the formation of cyclopropane products that had incorporated the ketone or aldehyde (20). In the case of 19a, the reactions typically led to a mixture of stereoisomers. 

Methyl vinyl Diethyl malonate Ethyl 2-carboethoxy-5-oxohexanoate... 

Like diethyl malonate, ethyl acetoacetate undergoes Michael addition to an a, /3-unsaturated ketone. 

Grossman, R. B. Vamer, M. A. Selective monoalkylation of diethyl malonate, ethyl cyanoacetate, and malononitrile using a masking group for the second acidic hydrogen. 

Malonic ethyl ester (20 gms.) is added gradually to a solution of sodium (3 gms.) in ethyl alcohol (40 c.c.). The solid sodium salt separates out, and when all the malonic ester has been added the solid mass is mixed with ethyl iodide (25 gms,), which is added gradually and which causes the mass to become liquid, The mixture is then heated on a water-bath for one and a half hours, by which time sodium iodide has separated out and no alkaline reaction is obtained,... 

Sodium (2-3 gms.) is dissolved in alcohol (30 gms.), and to the cold solution is added malonic ethyl ester (16 gms.). To the clear mixture, ether is added till a turbidity appears, and then iodine (12-7 gms.),... 

Tlie nitrile, prepared as above, is next digested with the calculated amount of sodium malonic ethyl ester, on the water-bath, till no alkaline reaction is obtained. After removal of the alcohol aud sodium chloride, the cyano-propyl-malonic ethyl ester is fractionally distilled nnder reduced pressure. B.p. 170°—175° at 40 mm. 

Structures of the same type have also been prepared by cationic polymerization techniques, as can be seen in Scheme 16. Vinyl ethers having isobutyl-, ac-etoxy ethyl-, and malonate ethyl- pendant groups have been used. Hydrolysis of... 

ALIPHATIC AND AROMATIC P-KETOESTERS FROM MONOETHYL MALONATE ETHYL 2-BUTYRYLACETATE... 

Huebner et al. studied the stoichiometry and approximate rates of oxidation of a number of compounds containing an active methylene group. They found that not all such compounds are oxidised by periodate, and that in general one of the activating groups must be -CHO or -COOH for oxidation to occur. Thus diethyl malonate, ethyl acetoacetate, and cyanoacetic acid are not oxidised. Acetylacetone and other acyclic 1,3-diketones are oxidised very slowly, but cyclic 1,3-diketones are readily oxidised (Wolfrom and Bobbitt ). The first step in the oxidation of a compound containing an active methylene group is hydroxylation, then this is followed by further oxidation, e.g. malonic acid and 1,3-cyclohexanedione react as follows... 

A rhodium-mediated carbene addition has been employed as the key step in a synthesis of furans. The precursors were synthesized on TentaGel-NHi resin, which was transformed into an amide (135). Subsequent formation of imides 136 with malonic ethyl ester chloride and reaction with tosyl azide gave solid-phase-bound diazo imides 137. Reaction with Rh2(OAc)4 in the presence of electron-deficient alkynes produced substituted furans 139 via the intermediate isomiinch-none 138 through a sequence of a [2-i-3]-cycloaddition to the alkyne and subsequent cycloreversion. The yields of the reaction varied in the range 50-70% (Scheme 36) [52]. 

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