Simple carboxylic acids

Decarboxylation of simple carboxylic acids takes place with great difficulty and is rarely encountered... 

TFA, Ph3P, NBS, CH2CI2, Pyr, 81-99% yield. This methodology can be used for the preparation of other amides from simple carboxylic acids. ... 

Simple carboxylic acids derived from open-chain alkanes are systematically named by replacing the terminal -e of the corresponding alkane name with -oic acid. The —C02H carbon atom is numbered Cl. 

Complexes of some simple carboxylic acids. C. Oldham, Prog. Inorg. Chem., 1968, 10, 223-258 (305). 

So do anhydrides and many compounds that enolize easily (e.g., malonic ester and aliphatic nitro compounds). The mechanism is usually regarded as proceeding through the enol as in 12-4. If chlorosulfuric acid (CISO2OH) is used as a catalyst, carboxylic acids can be ot-iodinated, as well as chlorinated or brominated. N-Bromosuccinimide in a mixture of sulfuric acid-trifluoroacetic acid can mono-brominate simple carboxylic acids. ... 

The name of a carboxylic acid always ends in -ic, and the name of the anion ends in -ate. Figure 17-9 shows three simple carboxylic acids formic acid ( K = 1.8 x 10 ), acetic acid ( K — 1.8 X 10 ), and benzoic acid ( Ta = 6.4 X 10 ). HCO2 is formate, CH3 CO2 is acetate, and Cg H5 CO2 is benzoate. Examples and treat benzoic acid quantitatively. 

OS 25] [R 4] [P 17] For dipeptide formation from the pentafluorophenyl ester of (J )-2-phenylbutyric acid and (S)-a-methylbenzylamine an extent of racemization of 4.2% was found [86]. At higher concentration (0.5 instead of 0.1 M), a higher degree of racemization was found (7.8%). This experiment also served to demonstrate monitoring of the racemization of a simple carboxylic acid used in peptide synthesis. 

The use of other simple carboxylic acid chlorides led to similar results the corresponding monoacyl- and diacyl-phospholes (23b,c and 26b,c) were formed. In these cases, the 2-acylphosphole (23b,c) was practically the only monoacylderiv-ative that was formed (Scheme 6) [27], The yields were all in the range of 21-50%. 

Simple carboxylic acids 10% Co/Si02 [19] Organic added to support... 

Gamma radiolysis of simple carboxylic acids and N-acetyl amino acids results in loss of the carboxyl group with formation of carbon monoxide and carbon dioxide. In the carboxylic acids, the ratio of C0/C02 produced is approximately 0.1, while in the N-acetyl amino acids the ratio is much smaller. In the poly carboxylic acids and poly amino acids, radiolysis also results in the loss of the carboxyl group, but here the ratio of C0/C02 is greater than 0.1. Incorporation of aromatic groups in the poly amino acids provides some protection for the carboxyl group. The degradation of the poly acids is believed to involve radical and excited state pathways. 

Based upon the observed radical and molecular product, it has been suggested by ourselves and others (3.4) that the major mechanism for the degradation of simple carboxylic acids is ... 

To name a simple carboxylic acid, follow the steps below. Figure 1.24 gives some examples of carboxylic acid names. 

Solubility in water Carboxylic acids with low molecular masses are very soluble in water. The first four simple carboxylic acids (methanoic acid, ethanoic acid, propanoic acid, and butanoic acid) are miscible with water. Like alcohols, ketones, and aldehydes, the solubility of carboxylic acids in water decreases as the number of carbon atoms increases. 

Glutamic acid is an example of an amino acid with an acidic side-chain. The pATa values are 2.19 (CO2H), 4.25 (Y-C02H), and 9.67 (NH2). Here, the y-carboxyl is more typical of a simple carboxylic acid. In strongly acidic solution, glutamic acid will... 

This problem covers a reaction sequence and a variety of different reactions, some easier than others. This one includes enolate anions, electrophilic cyclization, nucleophilic substitution, and simple carboxylic acid chemistry. 

A structurally very simple carboxylic acid, modafinil (62-4), increases alertness and inhibits narcolepsy as a result of its activity as a cerebral ai-adrenergic agonist. The short synthesis begins with the reaction of benzhydrol proper (62-1) with chloroacetic... 

The combinatorial reactions chosen for the novel amines were amide bond formation and sulfonamide formation. The novel carboxylic acids were derivatized to simple amides. For the amine reactions, we chose two simple carboxylic acids (propionic acid and benzoic acid) and two simple sulfonyl chlorides (methyl-sulfonyl chloride and benzenesulfonyl chloride) as the capping groups. Propyl amine and benzylamine were chosen as the capping groups to react with the novel carboxylic acids. Because only one reactant will be variable, these combinatorial libraries were essentially 1 x N libraries, where the one reactant was a simple reactant and the N component is the novel amines or acids. 

Simple carboxylic acids suffer photo-Kolbe decarboxylation under the usual photoelectrochemical conditions. In fact, this reaction type was one of the first characterized examples of oxidative cleavage of an organic molecule induced by long w avelength irradiation of a semiconductor. In the decarboxylation of acetic acid at... 

For a table of gas-phase acidities of 47 simple carboxylic acids, see Caldwell Rcnneboog Kebarle Can. J. Chem. 1989, 67, 611. 

A microscopic constant applies to a single site. Consider the dissociation of a simple carboxylic acid ... 

From these arguments it is clear that fluorination has a corresponding effect to diminish the basicity of a compound. For simple carboxylic acids the influence of fluorination on the reduction of basicity falls off dramatically with distance (vide supra).7 6 In gas-phase studies it is apparent that diminution of basicity can be attributed to an increase in the total array of atoms, each of which bears some electron density. Nevertheless, it is clear that when fluorine is attached directly to an anionic center such as that formed by a carboxylic acid its effect is substantially destabilizing.37 40... 

We have discussed the influence of substituents on acid strengths of simple carboxylic acids as though the full electrostatic effect of the substituent were exerted solely on the A// of ionization. However, careful thermodynamic analysis of acidities in aqueous solution show that entropy effects (Section 4-4B) are very important. This may seem surprising because entropy effects ought to be small for relative acid strengths, which can be assessed by the constants for simple equilibria such as Equation 18-3, in which (1) there are the same number of molecules on each side of the equation, and (2) the constraints on the species involved hardly seem different from one side of the equation to the other ... 

---