Acid converter

It is extensively used industrially as a catalyst, notably in the oxidation of sulphur dioxide to the trioxide in sulphuric acid manufacture. It is an essentially acidic oxide, dissolving in alkalis to give vanadates however, addition of acid converts the anionic vanadate species to cationic species, by processes which are very complex, but which overall amount to the following ... 

Dilute hydrochloric or sulphuric acid finds application in the extraction of basic substances from mixtures or in the removal of basic impurities. The dilute acid converts the base e.g., ammonia, amines, etc.) into a water-soluble salt e.g., ammonium chloride, amine hydrochloride). Thus traces of aniline may be separated from impure acetanilide by shaking with dilute hydrochloric acid the aniline is converted into the soluble salt (aniline hydrochloride) whilst the acetanilide remains unaffected. 

Drop 1 g. of sodium into 10 ml. of ethyl alcohol in a small flask provided with a small water condenser heat the mixture until all the sodium has dissolved. Cool, and add 1 g. of the ester and 0-5 ml. of water. Frequently the sodium salt of the acid will be deposited either at once or after boiling for a few minutes. If this occurs, filter oflF the solid at once, wash it with a little absolute ethyl alcohol (or absolute methylated spirit), and convert it into the p-bromophenacyl ester, p-nitro-benzyl ester or S-benzyl-tso-thiuronium salt (for experimental details, see Section 111,85). If no solid separates, continue the boiling for 30-60 minutes, boil oflF the alcohol, allow to cool, render the product just neutral to phenolphthalein with dilute sulphuric or hydrochloric acid, convert the sodium salt present in solution into a crystalline derivative (Section 111,85), and determine its melting point. 

One method of preparing sulphlnic acids has already been described (diazo reaction. Section IV,65). Reduction of a sulphonyl chloride with zinc powder and water affords the zinc salt of the sulphinic acid, converted by sodium carbonate to the sodium salt (in which form it is conveniently isolated), and by hydrochloric acid into the somewhat unstable sulphinic acid, for example ... 

Decane-1 10-dicarboxylic acid from sebacic acid. Convert sebacic acid into the acid chloride by treatment with phosphorus penta-chloride (2 mols) and purify by distillation b.p. 146-143°/2 mm. the yield is almost quantitative. Dissolve the resulting sebacoyl chloride in anhydrous ether and add the solution slowly to an ethereal solution of excess of diazomethane (prepared from 50 g. of nitrosomethylurea) allow the mixture to stand overnight. Remove the ether and excess of diazomethane under reduced pressure the residual crystalline 1 8-bis-diazoacetyloctane weighs 19 -3 g. and melts at 91° after crystaUisation from benzene. 

Boiling acetic acid converts 2-aminothiazole into the 2-acetamido derivative far more easily when catalytic amounts of diketene are added to the reaction mixture (277),... 

Oxidation of primary alcohols (Section 15 10) Potassi um permanganate and chromic acid convert primary al cohols to carboxylic acids by way of the corresponding aldehyde... 

In the confectionery industry, com symps are used extensively in nearly every type of confection, ranging from hard candy to marshmallows. In hard candies, which are essentially soHd solutions of nearly pure carbohydrates, com symp contributes resistance to heat discoloration, prevents sucrose crystallization, and controls hygroscopicity, viscosity, texture, and sweetness. Maltose symps, high conversion symps, and acid-converted symps (36 and 42 DE) are used for this appHcation. 

Com symps used in ice cream and fro2en desserts are generally 36- or 42-DE acid-converted symps. The symp serves primarily to provide maximum flexibiUty in adjusting flavor, texture, body, and smoothness. It also aids in grain control and in the modification of meltdown and shrinkage characteristics of the fro2en product. 

Tin does not react directly with nitrogen, hydrogen, carbon dioxide, or gaseous ammonia. Sulfur dioxide, when moist, attacks tin. Chlorine, bromine, and iodine readily react with tin with fluorine, the action is slow at room temperature. The halogen acids attack tin, particularly when hot and concentrated. Hot sulfuric acid dissolves tin, especially in the presence of oxidizers. Although cold nitric acid attacks tin only slowly, hot concentrated nitric acid converts it to an insoluble hydrated stannic oxide. Sulfurous, chlorosulfuric, and pyrosulfiiric acids react rapidly with tin. Phosphoric acid dissolves tin less readily than the other mineral acids. Organic acids such as lactic, citric, tartaric, and oxaUc attack tin slowly in the presence of air or oxidizing substances. 

The Sulfate Process. A flow diagram for the sulfate process is shown in Figure 1. The strongly exothermic digestion of the dried, milled feedstock in 85—95°/ sulfuric acid converts metal oxides into soluble sulfates, primarily titanium and iron. 

Mild acid converts it to the product and ethanol. With the higher temperatures required of the cyano compound [1003-52-7] (15), the intermediate cycloadduct is converted direcdy to the product by elimination of waste hydrogen cyanide. Often the reactions are mn with neat Hquid reagents having an excess of alkene as solvent. Polar solvents such as sulfolane and /V-m ethyl -pyrrol i don e are claimed to be superior for reactions of the ethoxy compound with butenediol (53). Organic acids, phenols, maleic acid derivatives, and inorganic bases are suggested as catalysts (51,52,54,59,61,62) (Fig. 6). 

Lime-Sulfuric. Recovery of citric acid by calcium salt precipitation is shown in Figure 3. Although the chemistry is straightforward, the engineering principles, separation techniques, and unit operations employed result in a complex commercial process. The fermentation broth, which has been separated from the insoluble biomass, is treated with a calcium hydroxide (lime) slurry to precipitate calcium citrate. After sufficient reaction time, the calcium citrate slurry is filtered and the filter cake washed free of soluble impurities. The clean calcium citrate cake is reslurried and acidified with sulfuric acid, converting the calcium citrate to soluble citric acid and insoluble calcium sulfate. Both the calcium citrate and calcium sulfate reactions are generally performed in agitated reaction vessels made of 316 stainless steel and filtered on commercially available filtration equipment. 

Cobalt in Driers for Paints, Inks, and Varnishes. The cobalt soaps, eg, the oleate, naphthenate, resinate, Hnoleate, ethyUiexanoate, synthetic tertiary neodecanoate, and tall oils, are used to accelerate the natural drying process of unsaturated oils such as linseed oil and soybean oil. These oils are esters of unsaturated fatty acids and contain acids such as oleic, linoleic, and eleostearic. On exposure to air for several days a film of the acids convert from Hquid to soHd form by oxidative polymeri2ation. The incorporation of oil-soluble cobalt salts effects this drying process in hours instead of days. Soaps of manganese, lead, cerium, and vanadium are also used as driers, but none are as effective as cobalt (see Drying). 

Cyclohexanone shows most of the typical reactions of aUphatic ketones. It reacts with hydroxjiamine, phenyUiydrazine, semicarbazide, Grignard reagents, hydrogen cyanide, sodium bisulfite, etc, to form the usual addition products, and it undergoes the various condensation reactions that are typical of ketones having cx-methylene groups. Reduction converts cyclohexanone to cyclohexanol or cyclohexane, and oxidation with nitric acid converts cyclohexanone almost quantitatively to adipic acid. 

Cobaltous acetate (4H2O) [6147-53-1] M 249.1, pKj 9.85 (for Co " "). Crystd several times as the tetrahydrate from 50% aqueous acetic acid. Converted to the anhydrous salt by drying at 80°/1mm for 60h. 

Dissolution of the cellulose in cuprammonium solution followed by acid coagulation of extruded fibre ( cuprammonium rayon —no longer of commercial importance). In this case the acid converts the cuprammonium complex back into cellulose. 

Organic acids convert the blue mesomerically stabilized phenolate anion to the red undissociated acid. Reductones (e.g. ascorbic acid) reduce the reagent to a colorless salt. 

B. 2HC1. PtCl. 3HjO, crystallises in yellow leaflets. The base gives a series of esters and also monoacyl derivatives. Hydriodic acid converts it into quitenol, and methyl iodide. 

Lawson " found that aconitine was converted by nitrous acid into a substance, C3jH40Oj2Nj, crystallising in small, colourless prisms, m.p. 276° (dec.). Jacobs and Craig confirmed this observation but prefer the formula C34H44O13N2. Nitric acid converts this nitroso-derivative into the nitronitroso-compound, 0311135013X3, described above. 

Anodic oxidation ui fluorosutfomc acid converts perfluoraalkyl methanols into perfluoroalkyl fluurondfates [4] (equation 42), (o-hydiododecafluorohexyl methanol can be converted to perfluorohexane-1,6-bisfluorosulfate when a higher ratio of Faraday charge per mole is applied 4] (equation 43)... 

Baeyer-Villiger oxidation by trifluoraperoxyacetic acid converts a chlo-rofluoroalkyl ketone into an ester 7l ] (equation 63)... 

The conversion of cyclic sulfides to sulfones is accompbshed by more energetic oxidations. Perhalogenated thiolanes [106] and 1,3-dithietanes [107] are oxidized to sulfones and disulfones, respectively, by a mixture of chromium trioxide and nitric acid (equation 98) The same reagent converts 2,4-dichloro-2,4-bis(tnfluoromethyl)-l,3-dif/u cto cs to disulfone derivatives [107], whereas trifluoromethaneperoxysulfonic acid converts the starting compound to a sul-fone-sulfoxide derivative [2(equation 99). 

Water adds to the triple bond of perfluorobutylalkynols in refluxing 98% formic acid to give the perfluorobutyl keto alcohol Methanolic potassium hydroxide or prolonged reflux m formic acid converts the keto alcohol to 2,2-dimethyl-5-perfluoropropyl-2,2-dimethylturan-3(2//)-one [2] (equation 3). 

The action of hydriodic acid on gdycerol is typical of the polyhychic alcohols. Hychiodic acid converts erythritol into secondary butyl iodide, and mannitol into secondaiy hexyl iodide. The normal iodides are never formed. 

Quinoline.—The formation of c[uinoline by Skratip s reaction may be explained as follows - The sulphuric acid converts the glycerol into aciolein, which then combines w-ith the aniline to form acrolein-aniline. The latter on o.xidation with nitrobenzene yields quinoline. 

The reaction is based on an early observation by Angeli and Ahrens that Piloty s acid converted aldehydes to hydroxamic acids, and this has formed the basis of the Angeli-Rimini aldehyde test. Di Maio and Tardella propose the above reaction sequence, consistent with the observed second-order kinetics. The possibility that benzenesulfon-hydroxamic acid would decompose in alkali to give nitroxyl (HNO)... 

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