Malonic acid ethyl ester

Substituted glutaric acids [29] were obtained from the ethyl malonic acid ester of the Baylis-Hillman product 14. The enolate of this ester, generated with LDA at -78 °C rearranged to give the substituted glutaric acids in good yield (Scheme 5.1.18). 

These compounds yield, on hydrolysis, the free acids, which, like all acids containing two carbo.xyl groups attached to the same carbon atom, lose COj on heating. Thus, ethyl malonic acid yields butyric acid. In this way the synthesis of monobasic acids may be readily effected. Malonic ester, moreover, may be used in the preparation of cyclic compounds as well as of tetrabasic and also dibasic acids of the malonic acid series ( Perkin). To give one illustration malonic ester, and ethylene bromide in presence of sodium alcoholate, yield triniethyleiic dicarbo.xylic ester and tetramethylene tetracarbo.xylic ester. The first reaction takes place in two steps,... 

The ethyl malonic ester (10 gms.) is hydrolysed by boiling for an hour on the water-bath with strong aqueous potash containing 15 gms. of potash. The product is treated with moderately strong hydrochloric acid till neutral, and the acid is then precipitated as the calcium salt by adding a concentrated solution of calcium chloride. The salt is filtered and decomposed by strong hydrochloric acid and the free ethyl malonic acid extracted with ether. The ether extract deposits crystals on evaporation, and these may be recrystallised from a small quantity of boiling water. Colourless prisms, m.p, 111 5°, Yield, about 5 gms. 

Phenyl ethyl malonic acid diethyl ester Methylurea... 

Methyl ethyl acetic acid may be prepared from methyl ethyl malonic ester by hydrolysis and subsequent heating of the methyl ethyl malonic acid.1 The yield by this method, in the preparation of large quantities, is about 61 per cent of the theoretical amount based on the malonic ester used. The acid was first prepared by Saur2 from methyl ethyl acetoacetic ester. It has also been made by oxidation of the corresponding aldehyde with chromic acid.3... 

Ethyl malonic acid, 162. Ethy malonic ester, 161. 

It is prepared by the interaction of diethyl ester of ethyl malonic acid and iso-pentyl chloride in the presence of sodium metal, when ethyl is isopentyl ester of diethyl malonic acid is obtained as an intermediate compound. This on condensation with urea in the presence of sodium ethoxide results into the formation of amobarbital. 

In the first step the diethyl ester of malonic acid is treated with ethyl bromide in the presence of sodium ethoxide when one of the active hydrogen atoms in the former gets eliminated with bromine atom in the later as a molecule of hydrobromic acid resulting into the formation of the corresponding diethyl ester of ethyl malonic acid. This on subsequent addition of 2-monobromopentane and in the presence of sodium ethoxide gives rise to diethyl ether of ethyl-(l-methyl butyl) malonate with the elimination of one molecule of hydrobromic acid. Urea is made to condense with the product obtained from the previous step when pentobarbital is formed with the elimination of two moles of ethanol. Finally, the pentobarbital is treated with a calculated amoimt of sodium hydroxide when the required official compoimd is formed. 

Diethyl malonate on reaction with sodium metal gives rise to sodium malonic ester which on treatment with ethyl bromide results into the formation of diethyl ester of ethyl malonic acid with the elimination of hydrobromic acid. The resulting ester on further reaction with 2-bromopentane gives the desired eompound, i.e., diethyl ester of ethyl (1-methyl butyl) malonic acid which on subsequent treatment with thiourea forms thiopental with the elimination of two moles of ethanol. Ultimately, the enol-iorm of thiopental when reaeted with a ealeulated amoimt of sodium hydroxide, it gives thiopental sodium. 

It may be prepared by the condensation of [2-(phenylsulfinyl) ethyl]- malonic acid diethyl ester with hydrazobenzene in the presence of sodium ethoxide in absolute ethanol. Completion of reaction is achieved by the addition of xylene and subsequent heating at about 130°C whereby the ethanol liberated as a produet of eondensation is removed eompletely. The crude product is extracted with a suitable solvent and finally recrystallized from ethanol. 

C]phenyl ethyl malonic acid diethyl ester and, finally, the condensation of this ester with urea. 

Carboxylic acids from malonic acid esters via malonic acids. A suspension of ethyl a-carbethoxy-y-oxo-5-phthalimidovalerate in 48%-HBr allowed to stand at room temp, overnight, then heated on a steam bath until dissolved, allowed to cool, and evaporated to dryness in vacuo a-carboxy-y-oxo-<5-phthalimido-valeric acid (Y 83.0%) heated to 170 /3-4 mm until gas evolution ceases -phthalimidolevulinic acid (Y 90.7%). D. P. Tschudy and A. Collins, J. Org. Chem. 24, 556 (1959). 

C21H40O4 2-ethyl-malonic acid dioctyl ester 1113-95-7... 

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 ... 

Compounds which dissolve in concentrated sulphuric acid may be further subdivided into those which are soluble in syrupy phosphoric acid (A) and those which are insoluble in this solvent (B) in general, dissolution takes place without the production of appreciable heat or colour. Those in class A include alcohols, esters, aldehydes, methyl ketones and cyclic ketones provided that they contain less than nine carbon atoms. The solubility limit is somewhat lower than this for ethers thus re-propyl ether dissolves in 85 per cent, phosphoric acid but re-butyl ether and anisole do not. Ethyl benzoate and ethyl malonate are insoluble. 

Alcohols, esters (but not ethyl benzoate, ethyl malonate or ethyl oxalate), aldehydes, methyl ketones and cyclic ketones containing less than nine carbon atoms as well as ethers containing less than seven carbon atoms are soluble in 85 p>er cent, phosphoric acid. 

Hydrogenolysis of the diallyl alkylmalonate 757 with formic acid in boiling dioxane affords the monocarboxylic acid 758. Allyl ethyl malonates are converted into ethyl carboxylates[471]. The malonic allyl ester TV-allylimide 759 undergoes smooth deallylation in refluxing dioxane to give the simple imide 760(472]. The allyl cyanoacetate 761 undergoes smooth decarboxylation to give... 

Ethylmalonic Acid.—Like acetoacetic ester (see p. 83), diethylmalonate contains the gioup CO.CHj.CO. By the action of sodium or sodium alroholate, the hydrogen atoms of the methylene group are successively replaceable by sodium. The sodium atoms are in turn replaceable by alkyl or acyl groups. Thus, in the present preparation, ethyl malonic ester is obtained by the action of ethyl iodide on the monosodium compound. If this substance be treated with a second molecule of sodium alcoholate and a second molecule of alkyl iodide, a second radical would be in roduced, and a compound formed of the general formula... 

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°. 

Dicyclohexylcarbodiimide n-Butyl Malonic Acid Ethyl Ester Hydra 2oben2ene... 

N-Phenyl-N-(2-emino5[Pg.360]

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