Monocarboxylic acid salts

In this method, an oligoethylene glycol is treated with 0.3 eq. of sodium bromoace-tate in methanol. The resulting monocarboxylic acid salt is then treated with toluene-sulfonyl chloride, sodium carbonate and dioxane. After heating the reaction mixture at 50° for an hour, the product was obtained either by Kugelrohr distillation or extraction. The two compounds produced in the reaction below (i.e., n = 1 and n = 2) were formed in 38% and 42% yields respectively . 

The present method for preparing aromatic dicarboxylic acids has been used to convert phthalic or isophthalic acid to tereph-thalic acid (90-95%) 2,2 -biphenyldicarboxylic acid to 4,4 -biphenyldicarboxylic acid 3,4-pyrroledicarboxylic acid to 2,5-pyr-roledicarboxylic acid and 2,3-pyridinedicarboxylic acid to 2,5-pyridinedicarboxylic acid. A closely related method for preparing aromatic dicarboxylic acids is the thermal disproportionation of the potassium salt of an aromatic monocarboxylic acid to an equimolar mixture of the corresponding aromatic hydrocarbon and the dipotassium salt of an aromatic dicarboxylic acid. The disproportionation method has been used to convert benzoic acid to terephthalic acid (90-95%) pyridine-carboxylic acids to 2,5-pyridinedicarboxylic acid (30-50%) 2-furoic acid to 2,5-furandicarboxylic acid 2-thiophenecar-boxylic acid to 2,5-thiophenedicarboxylic acid and 2-quinoline-carboxylic acid to 2,4-quinolinedicarboxylic acid. One or the other of these two methods is often the best way to make otherwise inaccessible aromatic dicarboxylic acids. The two methods were recently reviewed. ... 

Such a dispersant formulation for dispersing oil contains a mixture of a sorbitan monoester of an aliphatic monocarboxylic acid, a polyoxyethylene adduct of a sorbitant monoester of an aliphatic monocarboxylic acid, a water-dispersible salt of a dialkyl sulfosuccinate, a polyoxyethylene adduct of a sorbitan triester or a sorbital hexaester of an aliphatic monocarboxylic acid, and a propylene glycol ether as solvent [311,312]. 

A dispersant that can be used in drilling fluids, spacer fluids, cement slurries, completion fluids, and mixtures of drilling fluids and cement slurries controls the rheologic properties of and enhances the filtrate control in these fluids. The dispersant consists of polymers derived from monomeric residues, including low-molecular-weight olefins that may be sulfonated or phosphonated, unsaturated dicarboxylic acids, ethylenically unsaturated anhydrides, unsaturated aliphatic monocarboxylic acids, vinyl alcohols and diols, and sulfonated or phosphonated styrene. The sulfonic acid, phosphonic acid, and carboxylic acid groups on the polymers may be present in neutralized form as alkali metal or ammonium salts [192,193]. 

It is not only sodium salts of monocarboxylic acids that are effective nucleating agents for PET lithium, calcium and barium salts of monocarboxylic acids have also been found to impart nucleation ability [33],... 

The synthesis of the four monocarboxylic acids of dibenzothiophene has been recorded in the previous review. However, several modified preparations have since been described. Ethyl 1-dibenzothiophene-carboxylate has been synthesized from 2-allylbenzo[6]thiophene (Section IV,B, 1) hydrolysis afforded the 1-acid (57% overall). In a similar manner, 3-methyl-1-dibenzothiophenecarboxylic acid was obtained from the appropriately substituted allyl compound. This method is now the preferred way of introducing a carbon-containing substituent into the 1-position of dibenzothiophene. 2-Dibenzothiophenecarboxylic acid has been prepared by oxidation of the corresponding aldehyde or by sodium hypoiodite oxidation of the corresponding acetyl compound. Reaction of 2-acetyldibenzothiophene with anhydrous pyridine and iodine yields the acetyl pyridinium salt (132) (92%), hydrolysis of which yields the 2-acid (85%). The same sequence has been carried out on 2-acetyldibenzothiophene 5,5-dioxide. The most efficient method of preparing the 2-acid is via carbonation of 2-lithio-... 

Rosin, a brittle solid, mp 80 °C, is obtained from the gum of trees and tree stumps as a residue after steam distillation of the turpentine. It is made of 90% resin acids and 10% neutral matter. Resin acids are tricyclic monocarboxylic acids of formula C20H30O2. The common isomer is 1-abietic acid. About 38% of rosin is used as paper size (its sodium salt), in synthetic rubber as an emulsifier in polymerization (13%), in adhesives (12%), coatings (8%), and inks (8%). 

Similarily, the 4,14-dicarboxylic acid 56 with C2-symmetry could also be resolved via its 1-phenylethylamine salts and its configuration unambiguously correlated with the monocarboxylic acid 55 through the monobromo derivative 5878). Accordingly 55 and 56 with the same sign of optical rotation have the same chirality. Many racemic and optically active homo- and heterodisubstituted 4,12- and 4,14-disubstituted [2.2]metacyclophanes have been prepared and chemically correlated 78,79) mainly to study their chiroptical properties78). Whereas 4,12-homodisubstituted compounds have a center of inversion ( -symmetry) and are therefore achiral meso-forms , the corresponding 4,14-isomers are chiral with C2-symmetry. All heterodisubstituted products are chiral (Q-symmetry see also Section 2.9.4 for the discussion of their chiroptical properties and their use as models for the application of the theory of chirality functions). 

As an example of the application of the aforementioned sequence, Table XYI lists the main engineering parameters necessary to design or optimize ED stacks equipped with AMV and CMV electromembranes (Table II) and committed to the recovery of the sodium salts of some weak monocarboxylic acids of microbial origin (i.e., acetic, propionic, and lactic acid) and of a strong inorganic acid (i.e., chloride acid), as estimated by Fidaleo and Moresi (2005a,b, 2006). 

Monocarboxylic acids might be present in Murchison as free acids, esters or salts nothing is known about this aspect of the problem 38 They are relatively abundant in Murchison, more abundant than aminoacids and hydrocarbons. The relative concentration of propanoic acid with respect to propane is 205, while the ratio is 22 if propanoic acid is compared to glycine. So far, 17 dicarboxylic acids have been identified in Murchison. The lack of reference compounds precludes the identification of many others 24). 

The relative concentration of dicarboxylic acids with respect to aminoacids is higher (by one or two orders of magnitude). As in the case of monocarboxylic acids, every possible isomer seemed to be present, ranging from C2 to C5 molecules. In the case of chiral molecules, the two enantiomers coexisted in nearly equal concentration. Oxalic acid was detected as calcium salt, but the state of the other dicarboxylic acids in the Murchison meteorite remains an open problem 24 >. Dicarboxylic acids, as monocarboxylic acids, seem to be the result of synthetic pathways that give mixtures at random 44-45... 

If tho acid sodium salt of this bo digested with water, carbon dioxide is liberated and the sodium salt of diacetylene-monocarboxylic acid is formed c C.COOH C CII... 

Of the unsaturated monocarboxylic acids, undecylenic acid and oleic acid have been investigated by Rohland.2 Both yielded, on electrolyzing their potassium salts in aqueous solution, a mixture of unsaturated hydrocarbons, the nature of which was not determined. 

Yon Miller and Hofer 3 have also carried out the principle of the electrolysis of mixtures, discussed under malonic acid, using potassium ethyl succinate, and submitting the latter to electrolysis at the anode with potassium salts of monocarboxylic acids. They thus obtained on the addition of potassium acetate about 69% of the theoretical quantity of butyric ethyl ester ... 

The list of acids isolated from aqueous extracts of the shale is given for comparison. These acids were identified in the water extracts from raw Aleksinac shale as well as from bitumen-free shale, i.e., before and after the extraction of the bitumen (21). Mass spectrometric identifications of various isomers were based on comparison of the relative intensities of molecular ions and their corresponding base peak ions. The compounds extracted with water from the bitumen-free shale were very similar to the compounds isolated from the raw shale. The findings suggest that the acids were present as salts in both instances. In the aqueous extracts aromatic and dicarboxylic acids predominated, while aliphatic monocarboxylic acids were absent. Comparison of the chemical nature of water extractable acids with the acids obtained from the bitumen of the same shale showed a similarity in the type and range of aromatic and saturated unbranched dicarboxylic acids. 

The inorganic component was largely halite (NaCl), sea salt. Among the NaCl crystals, small objects of apatite were identified as the scales of small fish (Fig. 9.2). The organic compounds were monocarboxylic acids, a,(n-dicarboxylic acids, and... 

Lactate, either as a salt or in its undissociated form (lactic acid), is present in minor quantities in our food. However, inside our body this monocarboxylic acid plays an important role in the exchange of substrates between organs. In this regard, lactate cannot be considered as a dead-end product of the anaerobic glycolytic pathway, but represents a substantial source of energy stored in carbohydrate during exercise and after a carbohydrate-rich meal (Brooks, 1991). 

Carbon-11 labelled calcium channel antagonists C-nifedipine, C-nisoldipine, C-nitrendipine and C-CFj-nifedipine possessing vasodilating and hypotensive properties have been synthesized using a modified Hantzsch-type cyclocondensation proce-dure . Condensation of aldehydes 242, 243 and 244 with 3-aminocrotonic acid esters 245, 246, 247 and with acetoacetic ester 248 produced in one pot after 12 hours reflux in dry ethanol the methyl sulphonylethyl protected dihydropyridines 249-252. Deprotection of the carboxylic acids by alkaline hydrolysis followed by conversion into the dihydropyridine monocarboxylic acids 253-256 gave potassium salts in situ, and subsequent methylation with CH3I produced the corresponding labelled title compounds 257-260 (equation 102),... 

Acutally, better yields of the monocarboxylic acid esters are obtained by pyrolyzing the half-neutralized acid instead of the dipotassium salt. Even so, the yield of ester is only about 25%. 

Table 7. Summary of the inter-carboxyl hydrogen bonds in some Type A acid salts of monocarboxylic acids, MHX 2...

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