Some electrolytic syntheses

Hydrocarbons and di-esters, otherwise rather Inaccessible in a pure state, are eonvenimitly prepared by electrolytic (anodic) sjmthesis. Thus simple coupling 

Electrolysis, under similar conditions, of a mixture of two carboxyUc acids RCOOH and R COOH leads, in addition to normal coupling products R—R and R —R, to cross coupling R— R. If a mixture of a saturated carboxylic add and a half-ester of an ouo-dicarboxylic acid is electrolysed, there are three main products, viz., a hydrocarbon (I), a mono-ester (II), and a di-ester (HI) and these are readily separable by distillation. Some unsaturated ester (IV) is often present in small quantity. 

By increasing the molar proportion of the mouocarboxylic acid, the yield of (II) is improved. Thus dectrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIII) and sebacic acid (IX)  

An excellent synthesis of myristic acid is thus achieved from readily accessible starting materials. An alternative synthesis of myristic acid utilises hexanolc acid (M-caproic acid n-hexolc acid) (X) (2 mols) and methyl hydrogen sebacate (XI) (1 mol) the products, after hydrolysis, are n-decane (XII), myristic acid (XIII) and hexadecane-1 16-dicarboxylic acid (XIV)  

Sebacic acid. Dissolve 40 g. of methyl hydrogen adipate in 100 ml. of absolute methanol to which 0-1 g. of sodium has been added. Pass a current of about 2 0 amps, until the pH of the solution is about 8 (co. 6 horns) test with B.D.H. narrow-range indicator paper. Transfer the contents of the electrolysis cell to a 600 ml. round-bottomed flask, render neutral with a little acetic acid, and distil off the methanol on a water 

Electrolysis cell. This is shown in Fig. VI, 31, 1 and is almost self-explanatory. The cylindrical cell of Pyrex glass (6 long by 2f diameter) is cooled by immersion in a cooling bath. The electrodes consist of two platinum plates (4 cm. X 2-5 cm. X 0-3 mm.), which are placed about 2 mm. apart. The temperature of the electrolyte is maintained at 30-35° by means of the internal cooling coil and also by immersion of the cell in ice-water. A current of 1 5-2 0 amperes is passed until the electrolyte becomes slightly alkaline, which normally takes about 20-50 per cent, longer than the calculated time on the basis of the current and the amounts of acid employed. It is advantageous to reverse the direction of the current occasionally. 

2CHjOOC(CHis)4COO------ CH300C(CHj) C0OCH3 + 2CO3 + 2e 

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Picolyl ethers are prepared from their chlorides by a Williamson ether synthesis (68-83% yield). Some selectivity for primary versus secondary alcohols can be achieved (ratios = 4.3-4.6 1). They are cleaved electrolytically ( — 1.4 V, 0.5 M HBF4, MeOH, 70% yield). Since picolyl chlorides are unstable as the free base, they must be generated from the hydrochloride prior to use. These derivatives are relatively stable to acid (CF3CO2H, HF/anisole). Cleavage can also be effected by hydrogenolysis in acetic acid. ... 

Picolyl ethers are prepared from their chlorides by a Williamson ether synthesis (68-83% yield). Some selectivity for primary vs. secondary alcohols can be achieved (ratios = 4.3-4.6 1). Picolyl ethers are cleaved electrolytically ( —1.4 V,... 

Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) are members of a family of so-called natriuretic peptides, synthesized predominantly in the cardiac atrium, ventricle, and vascular endothelial cells, respectively (G13, Y2). ANP is a 28-amino-acid polypeptide hormone released into the circulation in response to atrial stretch (L3). ANP acts (Fig. 8) on the kidney to increase sodium excretion and glomerular filtration rate (GFR), to antagonize renal vasoconstriction, and to inhibit renin secretion (Ml). In the cardiovascular system, ANP antagonizes vasoconstriction and shifts fluid from the intravascular to the interstitial compartment (G14). In the adrenal cortex, ANP is a powerful inhibitor of aldosterone synthesis (E6, N3). At the hypothalamic level, ANP inhibits vasopressin secretion (S3). It has been shown that some of the effects of ANP are mediated via a newly discovered hormone, called adreno-medullin, controlling fluid and electrolyte homeostasis (S8). The diuretic and blood pressure-lowering effect of ANP may be partially due to adrenomedullin (V5). 

Chromium (II) chloride solutions can be prepared by any one of several different procedures. If pure electrolytic chromium is available, the procedure of Holah-Fackler (see synthesis 4) is recommended. Some modification as noted at the end of this procedure may be desirable. If metallic chromium is not available, commercial chromium(III) chloride may be reduced electrolytically (a suitable divided cell is needed), or the reduction may be effected by zinc and hydrochloric acid. The latter procedure, which starts with the most commonly available reagents and apparatus, is described here. 

Cost and commercial availabiUty More and more lab suppliers and a few large-scale suppliers offer ionic Uquids. For a more frequent use of these solvents the commercially available variety has to be increased and cost should be reduced. There is good reason that cost reductions will be possible in the near future because at least some of the ionic liquids will potentially find use in very large apphcations besides catalysis. They are discussed for fuel desulfurization, separations, hquefication, gasification and chemical modification of sohd fuels, as electrolytes or in connection with synthesis and apphcation of new materials. Also apphcations such as azeotrope-breaking liquids, thermal fluids or lubricants are under consideration. Because of economy of scale in combination with such apphcations, the price of the solvent will decrease significantly. 

After Michael Faraday revealed the fundamental experiments of electrolytic reactions in 1834, Kolbe carried out the electrolysis of salts of monobasic aliphatic acids producing hydrocarbons, which was the first application of the method to organic synthesis (1854). It needed another hundred years before Wilson found that some acrylic ester derivatives were polymerized at the cathode instead of being reduced in... 

Synthesis of monomers for the preparation of the methyl ester polyisocyanides begin with a-amino acid esters. These polyisocyanides were developed to yield optically active polymers which could be characterized first as non-electrolytes, and, after hydrolysis, as polyelectrolytes in aqueous media. As predicted, poly[a(carboxymethyl) alkyl isocyanides] are soluble in various solvents. Unfortunately, a low ceiling temperature, some instability to alkali and especially to... 

The direct electrochemical synthesis of metal alkoxides by the anodic dissolution of metals into alcohols containing conducting electrolytes was initially demonstrated by Szilard in 1906 for the methoxides of copper and lead.19 More recently the method has received some attention particularly in the patent literature.29-25 The preparation of the ethoxides of silicon, titanium, germanium, zirconium and tantalum by electrolysis of ethanolic solutions of NH Cl has been patented, although the production of the ethoxides was found to cease after several hours.24,25... 

Alcoholics with chronic liver disease may have disorders of fluid and electrolyte balance, including ascites, edema, and effusions. These factors may be related to decreased protein synthesis and portal hypertension. Alterations of whole body potassium induced by vomiting and diarrhea, as well as severe secondary aldosteronism, may contribute to muscle weakness and can be worsened by diuretic therapy. Some alcoholic patients develop hypoglycemia, probably as a result of impaired hepatic gluconeogenesis. Some alcoholics also develop ketosis, caused by excessive lipolytic factors, especially increased cortisol and growth hormone. 

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