Sodium malonic diethyl ester

Hydrochloric acid [7647-01-0], which is formed as by-product from unreacted chloroacetic acid, is fed into an absorption column. After the addition of acid and alcohol is complete, the mixture is heated at reflux for 6—8 h, whereby the intermediate malonic acid ester monoamide is hydroly2ed to a dialkyl malonate. The pure ester is obtained from the mixture of cmde esters by extraction with ben2ene [71-43-2], toluene [108-88-3], or xylene [1330-20-7]. The organic phase is washed with dilute sodium hydroxide [1310-73-2] to remove small amounts of the monoester. The diester is then separated from solvent by distillation at atmospheric pressure, and the malonic ester obtained by redistillation under vacuum as a colorless Hquid with a minimum assay of 99%. The aqueous phase contains considerable amounts of mineral acid and salts and must be treated before being fed to the waste treatment plant. The process is suitable for both the dimethyl and diethyl esters. The yield based on sodium chloroacetate is 75—85%. Various low molecular mass hydrocarbons, some of them partially chlorinated, are formed as by-products. Although a relatively simple plant is sufficient for the reaction itself, a si2eable investment is required for treatment of the wastewater and exhaust gas. 

The starting material is prepared by reacting 2-amino-6-methylpyridine with ethoxymethyl-ene-malonic acid diethyl ester and then reacting that product with sodium hydroxide. 

The starting material may be produced by reacting 6-amino-2-methylthiopyrimidine with ethoxymethylene malonic acid diethyl ester. The intermediate thus produced is converted by boiling in diphenyl ether to 6-ethoxycarbonyl-2-methylthio-5-oxo-5,B-dihydropyrido-[2,3-d]pyrimidine. That is hydrolyzed by sodium hydroxide to cleave the ethoxy group and then ethylated with diethyl sulfate to give the starting material. 

Nit ropheny I) pyridine Ethoxymethylene malonic acid diethyl ester Ethyl iodide Sodium hydroxide... 

MALONALDEHYDE, NITRO-, SODIUM DERIVATIVE, 32, 95 Malonic acid, 31, 35 33, 20, 62 Malonic acid, ethylidene, diethyl ESTER, 32, 54... 

Preparation of the intermediate for Allobarbitone (diethyl diallyl malonate). Diethyl malonate is dissolved in anhydrous alcohol and treated with one mole of clean sodium meted per every one mole of the ester. To this solution add one mole of allyl chloride and reflux for about 4 hours. Another equimolar ratio (1 mole of sodium per mole of ester) of sodium is added, followed by the same ratio of allyl chloride (1 mole per 1 mole), and this mixture is boiled for 2 hours. The alcohol is removed by distillation and the ester is extracted with benzene and distilled or evaporated in vacuo, recrystallized with a suitable "dry" solvent, and filtered. Evaporate again to remove traces of solvent. Keep this product, and any other substances that require dry reagents or solvents, stored away from contact with the atmosphere. When evaporating, filter the air coming into the evaporating vessel with a suitable drying agent. Use a little common sense. 

When treated with one equivalent of sodium ethoxide, diethyl malonate is converted into the mono-sodio derivative, as a result of removal by base of one of the a-methylene protons to yield a mesomeric anion (12). This nucleophilic anion undergoes an S 2 reaction with an alkyl halide to give a C-substituted malonic ester. A second, different, alkyl group can be similarly introduced on to the a-carbon atom, or alternatively two identical alkyl groups may be introduced in a one-step operation by using appropriate proportions of reactants. 

By interaction of malonic acid diethyl ester with sodium ethylate (molar ratio 1 1) and then with ethyl bromide (molar ratio 1 1) was prepared ethylmalonic... 

Diethyl ester of malonic acid Sodium ethylate... 

Amino-6-methylpyridine Ethoxymethylene malonic acid diethyl ester Sodium hydroxide Ethyl iodide... 

An aqueous solution of sodium nitrite that is treated with HC1 contains nitrosyl cations 0=N . These can react with the enol E of the malonic acid diethyl ester (cf. Figure 12.9, bottom). First, a nitroso compound (F) is formed, which then undergoes acid-catalyzed isomerization to give the oxime A. Usually, the oxime is reduced by zinc, which is dissolved in acetic acid, to yield an amine that normally undergoes in situ acetylation in acetic acid. In this way the (acetamido)malonic acid diethyl ester B is obtained as the reduction/acetylation product, which can be employed, for example, in the synthesis of amino acids (Figure 13.39). 

One equivalent of NaOEt in EtOH deprotonates malonic acid diethyl ester completely to give the sodium enolate A (Figure 10.33). This enolate is monoalkylated upon addition of an alkylating reagent such as BuBr, and a substituted malonic ester C is formed. During the alkylation reaction, the substituted malonic ester C reacts to a certain extent with some of the enolate A, resulting in the butylated enolate B and unsubstituted neutral malonic ester. It is for this reason that the reaction mixture contains two nucleophiles— the original enolate A and the butylated enolate B. The alkylation of A with butyl bromide is much faster than that of B, since A is less sterically hindered than B. The main product is therefore the product of monoalkylation. Distillation can be used to separate the main product from small amounts of the product of dialkylation. 

Sodio diethyl malonate Malonic acid, diethyl ester, ion(l-), sodium (8) Propanedioic acid, diethyl ester, ion(l-), sodium (9) (996-82-7) 3-Formylquinoline-2( l//)-thione 3-Quinolinecarboxaldehyde, 1,2-dihy-dro-2-thioxo- (9) (51925-41-8)... 

Sodium hydrosulfide was found to afford a thiirane 67 upon reaction with 2-iodomethylcyclopropane-l,l-dicarboxylic acid diethyl ester <2005TL469>. In addition, 2-allyl malonic ester 68 was obtained. Scheme 12 shows the reasonable mechanisms proposed by the authors. 

Quinoxaline-2-carboxaldehyde has been converted into the 2-carboxylic acid by oxidation with potassium permanganate in acetone and reduced to the 2-hydroxymethyl compound by treatment with formalin and potassium hydroxide. It also undergoes other typical reactions of aromatic aldehydes such as benzoin formation on reaction with potassium cyanide - and condensation reactions with malonic acid and its diethyl ester and Schiff base formation. Acid-catalyzed reaction of quinoxaline-2-carboxaldehyde with ethylene glycol gives the cyclic acetal the diethylacetal has been prepared by reaction of 2-dibromomethylquinoxaline with sodium ethoxide. " An indirect preparation of the oxime 11 is achieved by treatment of 2-nitromethyl-quinoxaline (10) with diazomethane followed by thermolysis of the resulting nitronic ester. 

The cyanoacetic acid obtained from monochloroacetic acid and sodium cyanide, is treated with hydrochloric acid and ethanol to yield the diethyl ester of malonic acid. The ester, in absolute ethanol, is reacted with the stoichiometric proportion of metallic sodium so as to replace only one active hydrogen of the methylene (CH2) group. Thereupon, a slight excess of the calculated amount of allyl bromide is added. The second replaceable hydrogen is abstracted with 1-methyl butyl bormide and the resulting product is made to react with a theoretical amount of thiourea to yield thiamylal. The free acid thus obtained is conveniently transformed into the official sodium salt by neutralization with a stoichiometric proportion of sodium hydroxide (1 1). 

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. 

Preparation of diethyl ester of allyl-(l -methyl butyl) malonate (//) Condensation of (/) above with urea and Hi) Preparation of the sodium salt. 

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. 

---