Ethyl adipate preparation

According to the literature, the product obtained in this manner may contain ethyl adipate. To remove this, the product is cooled to 0° and run slowly into 600 cc. of 10 per cent potassium hydroxide solution maintained at 0° with ice-salt. Water is added until the salt which separates has dissolved, and the cold alkaline solution is extracted twice with 200-cc. portions of ether. The alkaline solution, kept at 0°, is run slowly into 900 cc. of 10 per cent acetic acid solution with stirring, the temperature remaining below 1° (ice-salt). The oil which separates is taken up in 400 cc. of ether, and the aqueous solution is extracted with four 250-cc. portions of ether. The ether extract is washed twice with cold 7 per cent sodium carbonate solution and dried over sodium sulfate. After removal of the ether the residue is distilled, b.p. 7g-8i°/3 mm. The recovery is only 80-85 per cent, and in a well-conducted preparation the ethyl adipate eliminated amounts to less than one per cent of the total product. Unless the preparation has proceeded poorly the tedious purification ordinarily is best omitted. 

Carbethoxycyclopentanone has been prepared from ethyl adipate by the action of sodium,sodamide, and sodium ethylate. The method in the above procedure is based upon the work of Cornubcrt and Borrel. ... 

Alcohols are the most frequently formed products of ester hydrogenolysis. The hydrogenation of esters to alcohols is a reversible reaction with alcohol formation favored at high pressure, ester at low pressure (/). Copper chromite is usually the catalyst of choice. Details for the preparation of this catalyst (/7) and a detailed procedure for hydrogenation of ethyl adipate to hexamethylene glycol (/[Pg.80]

Sometimes the equilibrium is shifted by removing one of the products. An elegant way of doing this is illustrated by the preparation of ethyl adipate. The dicarboxylic acid adipic acid, an excess of ethyl alcohol, and toluene arc heated with a little sulfuric acid under a distillation column. The lowest boiling component (b.p. 75 ) of the reaction mixture is an azeotrope of water, ethyl alcohol, and toluene fcomoare Sec. 15.6) consequently, as fast as water is formed it is... 

In a steel reaction vessel (Note i), capable of withstanding high pressures with an adequate safety factor (Note 2) and having a capacity of 400 cc. or more, are placed 252 g. (1.25 moles) of ethyl adipate (b.p. i44-i45°/29 mm.) (Org. Syn. 17, 32) and 20 g. of copper chromite catalyst, prepared either with or without the addition of barium (p. 31). The reaction vessel is closed, made gas tight, and secured in a suitable agitating device. After connection is made with the hydrogen supply, hydrogen is introduced until a pressure of 2000 to 3000 lb. per sq. in. is reached (Note 2). 

Hexamethylene glycol has been prepared by treating hexa-methylene iodide with silver acetate and hydrolyzing the acetate, by hydrolyzing the bromide, by reducing ethyl adipate with sodium and alcohol, and by the method here described. The catalytic hydrogenation over copper-chromium oxide of the... 

This method with some slight modihcations is applied in the synthesis of to-bromo esters from Cs to Cn. Methyl 5-bromovalerate has been prepared by treating the silver salt of methyl hydrogen adipate with bromine. The ethyl ester has been prepared from the acid by esterification or through the acid chloride. ... 

Extension by three carbon atoms is possible with methyl glutarate [183], by the isoprene unit with ethyl 3-methyl adipate [184], by four carbon atoms with methyl adipate [143], by five carbon atoms with methyl pimelate [185] and by six carbon atoms with methyl suberate [186]. A series of branched -fluorocarboxylic acids were prepared by cross-coupling with oo-fluorocarboxylic acids [187]. For further examples see Tables 6, 7. 

Prepare 26 g. of molecular sodium in a 1500 ml. round-bottomed flask (Section II,50,d, Method 1). Cover the sodium with 625 ml. of sodium-dried A.R. benzene fit the flask with an efficient reflux condenser protected from the air by means of a calcium chloride (or cotton wool) guard tube. Add 151 5 g. of diethyl adipate (Sections 111,99 and 111,100) in one lot, followed by 1 6 ml. of absolute ethyl alcohol. Warm the flask on a water bath until, after a few minutes, a vigorous reaction sets in and a cake of the sodio compound commences to separate. Keep the flask well shaken by hand during the whole of the initial reaction. After the spontaneous reaction has subsided, reflux the mixture on a water bath overnight, and then cool in ice. Decompose the product with ice and dilute hydrochloric acid (1 1) add the acid until Congo red paper is turned blue. Separate the benzene layer, and extract the aqueous layer with 100 ml. of benzene. Wash the combined extracts with 100 ml. of 5 per cent, sodium carbonate solution and 160 ml. of water dry over a KWe anhydrous magnesium sulphate. Remove the benzene under atmospheric pressure (Fig. II, 13, 4, but with modified Claisen flask), and fractionate the residue under reduced pressure. Collect the 2-carbethoxy-epelopentanone at 108-111°/15 mm. (96 g.). Upon redistillation, the product boils at 102°/H mm. 

Thermoset polymeric esters consisting of neopentyl glycol, propylene glycol, trimethylol propane, adipic acid, maleic anhydride, and 2-ethyl hexanol were prepared by McAlvin et al. (3) and were used in blends containing styrene monomer. The mixture was cured by pultrusion and had improved weatherabil-ity characteristics. 

Preparation 413.—Diethyl Adipate [Di-ethyl ester of hexan di-add],... 

Acetyl-n-valeric acid has been prepared by the oxidation of 1-methylcyclohexene with potassium permanganate 5 by the oxidation of 2-methylcyclohexanone with chromic oxide and sulfuric acid 6 by the reaction of methylzinc iodide on the ethyl ester of adipic acid chloride and saponification of the ethyl ester of 5-acetyl-w-valeric acid so obtained 7 by the saponification of the ethyl ester of diacetylvaleric acid 2 and through the hydrolysis of ethyl a-acetyl-6-cyanovalerate with boiling 20% hydrochloric acid.3... 

A reaction kettle was charged with polyesterdiol (0.5 mol M 1000 daltons prepared from isophthalic acid, adipic acid and hexanediol), polyethylene glycol (0.05 mol Mw= 1500 daltons), and dimethylolpropanoic acid (1.25 mol) dissolved in methyl ethyl ketone. The mixture was heated to 80°C. When the reaction was completed the... 

The submitters report that ethyl hydrogen adipate, b.p. I55 IS7° at 7 mm-, has been prepared in 71-75 per cent yields on a one-mole scale by the same procedure. 

Oxygen-evolving PS II complexes which lack LHC II but still retain the three extrinsic proteins were prepared with 2.2% HTG from spinach PS II membranes [8,11]. The complexes were suspended in 40 mM Mes-NaOH (pH 6.5), 5 mM MgCl2, 10 mM NaCl and 0.4 M sucrose and stored at 77 K. A zero-length crosslinker, l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and succinimidyl esters with different chain lengths (disuccinimidyl-succinate, -adipate, -suberate and -sebacate which are called here DS 2, DS 4, DS 6 and DS 8, respectively) were used. For crosslinking, 15 jul of water solution of EDC (3 mg/ml) or 5 ul of dimethylsulfoxide solution of each disuccinimidyl ester (5 mg/ml) was added to 30-45 1 of sample suspensions containing 15-30 jig chlorophyll. After the mixture was incubated at room temperature for 10 min, the crosslinked complexes were treated with 8 M urea, 10% SDS and 2% 2-mercaptoethanol for 30 min at room temperature and applied to... 

Figure 4 Reaction scheme for ihe preparation of tyrosine-derived polyarylates. This reaction scheme is a copolymerization of a diphenol component and a diacid component. The diphenol components are the same desaminotyrosyl-tyrosine alkyl esters used in the synthesis of polycarbonates (Fiipire 3). The pendent chain Y is ethyl, butyl, hexyl, or octyl. The diatid components are succinic acid, adipic acid, suberic acid, and sebacic acid providing a flexible backbone spacer (R) having 2, 4, 6, and 8 methylene groups respectively. DIPC = diisopropylcarbodiimide.

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