Acids preparations

Chemical Properties. Like neopentanoic acid, neodecanoic acid, C2QH2QO2, undergoes reactions typical of carboxyHc acids. For example, neodecanoic acid is used to prepare acid chlorides, amides (76), and esters (7,11,77,78), and, like neopentanoic acid, is reduced to give alcohols and alkanes (21,24). One area of reaction chemistry that is different from the acids is the preparation of metal salts. Both neopentanoic acid and neodecanoic acid, like all carboxyHc acids, can form metal salts. However, in commercial appHcations, metal salt formation is much more important for neodecanoic acid than it is for neopentanoic acid. 

A second method for preparing acid salts is termed fusion, represented by... 

Purpurin [81-54-9] (179) is a usefiil iatemiediate for preparing acid-mordant dyes, and is prepared by oxidation of alizarin with manganese dioxide and sulfuric acid (145). 

In the former Soviet Union much use is made of industrial by-products to prepare acid inhibitors. The PB class is obtained by treating technical butyraldehyde with ammonia and polymerising the resulting aldehyde-ammonia. PB-5, for example, with O-Ol-O-15% of an arsenic salt is used in 20-25% HCl. A mixture of urotropine (hexamethyleneimine, hexamine) with potassium iodide, a regulator and a foaming agent is the ChM inhibitor. BA-6 is prepared from the condensation product of hexamine with aniline. A more recent development is the Katapin series which consists of /7-alkyl benzyl pyridine chlorides Katapin A, for example, is the /7-dodecyl compound. 

Know the correct procedure for preparing acid solutions. Always add the acid slowly to the water. 

The usual procedure of preparing acid azides, which involves treating an acid chloride with sodium azide,8,9 suffers from the disadvantage that it is often difficult to obtain pure acid chlorides in good yields from acids which either decompose or undergo isomerization in the presence of mineral acids.7 Synthesis of the azide by way of the ester and hydrazide10 has been used to circumvent this difficulty but is much less convenient. The present procedure permits ready formation of acid azides in excellent yields from mixed carboxylic-carbonic anhydrides and sodium azide under very mild conditions. 

Calculate the normality of the prepared acid from the data obtained. Write the molecular and net ionic equations of the neutralization reaction. 

Electrical Conductance of Acid Solutions. Pour prepared acid solutions into three dry beakers and check whether they conduct an electric current. Record the ammeter readings. On the basis of these experiments, arrange the acids in a series according to their activity. 

The mass spectrum of the bromosuccinic acid (K K Laboratories, Inc.), a snow-white powder which melted smoothly in the range of 160°-165°C, showed no peak corresponding to the parent compound. No impurities could be identified in particular, there were no peaks corresponding to fragments containing two bromine atoms. The mass spectrum for bromosuccinic acid was not found in the literature, but that of the prepared acid was analogous to the one for succinic acid, e.g., no parent peak (25). 

Acid Salts.—There are two general ways of preparing acid salts (1) the action of an acid upon a normal salt and (2) the partial neutralization of an acid. The following example will illustrate a convenient mode of procedure. 

Attempts to prepare acid anhydride derivatives by our methodology were unsuccessful. Various carboxylic acids were reacted with PCTFE in the presence of Cr(CO)6 in efforts to prepare anhydrides, but no appreciable reaction occurred in any case. The major side reaction in each case appears to have been formation of the carboxylated PCTFE derivative. 

Immobilized, highly reactive phenyl esters can be prepared by acylating resin-bound 4-acyl-2-nitrophenol (Entry 4, Table 3.13 [285-288]) or 4-(aminocarbonyl)-2,3,5,6-tetrafluorophenol (Entries 7 and 8, Table 3.13). These esters are similar to oxime esters (see Section 3.3.3.3), and even react with weak nucleophiles such as anilines or alcohols. This type of linker is not, therefore, well suited for long synthetic sequences on insoluble supports, but only for the preparation of simple acid derivatives. Because cleavage yields the unchanged phenol, these resins can be reused several times, which renders this strategy of preparing acid derivatives quite cost-effective. 

Most of these procedures are incompatible with common linkers, and are therefore unsuitable for the transformation of support-bound substrates into carboxylic acids. A more versatile approach for this purpose is the saponification of carboxylic esters. Saponifications with KOH or NaOH usually proceed smoothly on hydrophilic supports, such as Tentagel [19] or polyacrylamides, but not on cross-linked polystyrene. Esters linked to hydrophobic supports are more conveniently saponified with LiOH [45] or KOSiMe3 in THF or dioxane (Table 13.11). Alternatively, palladium(O)-mediated saponification of allyl esters [94] can be used to prepare acids on cross-linked polystyrene (Entries 9 and 10, Table 13.11). Fmoc-protected amines are not deprotected under these conditions [160],... 

A. Ch., [3], 37, 311.)—This is a standard method of preparing acid anhydrides. By using the sodium salt of one acid with the acid chloride of another, mixed anhydrides may be obtained. 

The acid-catalysed reaction of a dicarboxylic acid with an excess of alcohol yields the diester. However, the process may be adapted to prepare acid esters of dicarboxylic acids by using molar proportions of the diacid and alcohol (e.g. methyl hydrogen adipate, Expt 5.147). Alternatively the acid ester may be prepared by subjecting the diester to controlled partial hydrolysis with one molar proportion of potassium hydroxide. 

Only freshly prepared acid should be used. 

Preparation. Acids can be used as straight concentrated solutions or diluted to some degree with water. Some can be mixed (i.e., aqua regia three parts hydrochloric and one part nitric acid). Another mixed solution is peroxysulfuric acid. It is made by mixing a few milliliters (i.e., 5 mL) of concentrated H2SO4 with an equal amount of 30% H2O2. Warming (by steam) can often increase the effectiveness of an acid or oxidizer. 

Vegetable oils are refined through pressing/extraction, degumming, alkali deacidification, decolorization, and deodorization. Alkali deacidification byproduces soapstock. Acidulation of soapstock prepares acid oil which contains FFAs, acylglycerols, and other lipophilic compounds. It is reproduced currently as FFAs, which are used as raw materials for production of soaps, lubricants, and paints. But the demand for FFAs is almost in saturation. Hence, conversion of acid oil to BDF is expected to avoid an oversupply of the industrial FFAs and subsequent price decrease. 

The procednre for this synthesis is essentially the same as that for the n-butyl cyclo-propanecarboxylate described above. In the present case 3.8 g (0.12 mol) of methanol is used. [If commercially prepared acid chloride is used, add 8.80 g (0.06 mol).] Since... 

A convenient method for preparing acids from halides is through the cyanides. It is usually unnecessary to isolate or purify the cyanide. By this method the carbon content is increased by one carbon atom. Primary aliphatic nitriles are readily formed in high yields from the halides however, secondary and tertiary cyanides are less easily made in this... 

---