Caiboxylic acids

ANTIBACTERIALAGENTSSYNTHETIC - NITHOFURANS] (Vol2) 2-Acetoxy-9,10-dimethoxyl,3,4,6,7,llb-hexahydro-2FIben2o[a]qumoli2in-3-caiboxylic acid diethylamide [63-12-7]... 

AMINES-LOWERALIPHATIC AMINES] (Vol 2) b-Diethylammoethylanude. See Butoxyquinoline-4-caiboxylic acid. 

The most common O- and N-acylation procedures use acylating agents that are more reactive than caiboxylic acids or their esters. Carboxylic acid chlorides and anhydrides react rapidly with most unhindered hydroxy and amino groups to give esters and amides, respectively ... 

Caiboxylic acids aie exceedingly difficult to reduce. Acetic acid, for example, is often used as a solvent in catalytic hydrogenations because it is inert under the reaction conditions. A very powerful reducing agent is requued to convert a caiboxylic acid to a pri-maiy alcohol. Lithium aluminum hydride is that reducing agent. 

Sodium borohydride is not neaiTy as potent a hydride donor as lithium aluminum hydride and does not reduce caiboxylic acids. 

Esters aie more easily reduced than caiboxylic acids. Two alcohols aie fonned from each ester molecule. The acyl group of the ester is cleaved, giving a primary alcohol. 

The answer to this question is critical because it tells us whether the caibon-oxygen bond of the alcohol or a caibon-oxygen of the caiboxylic acid is broken during esterification. 

The thennal decarboxylation of malonic acid derivatives is the last step in a multistep synthesis of caiboxylic acids known as the malonic ester synthesis. This synthetic method will be described in Section 21.7. 

With p fa s of approximately 10, phenols aie stronger acids than alcohols, but weaker than caiboxylic acids. They aie converted quantitatively to phenoxide anions on treatment with aqueous sodium hydroxide. 

Abstract PAMAM types polyether based dendrimers were synthesized from three branched Jeffamines . Synthesized compounds bears metylester/ferf-butylester, caiboxylic acid or amine groups. In the synthesis iterative Micheal type of reaction paths were followed. Catalytic properties of the molecules were studied in homogenous phase. 

Reduction of the carboxylic acid group passes through the intermediate aldehyde. For a number of examples in the heterocyclic series, the aldehyde becomes a major product because it is trapped as the hydrated vfc.-diol form. Examples include imidazole-2-caiboxylic acid [139], thiazole-2-carboxylic acid [140] and pyridine-4-carboxylic acid [141] reduced in dilute aqueous acid solution. Reduction of imidazole-4-carboxylic acid proceeds to the primary alcohol stage, the aldehyde intermediate is not isolated. Addition of boric acid and sodium sulphite to the electrolyte may allow the aldehyde intermediate to be trapped as a non-reducible complex, Salicylaldehyde had been obtained on a pilot plant scale in this way by... 

Nicotinic acid and nicotinamide, members of the vitamin B group and used as additives for flour and bread enrichment, and as animal feed additive among other applications, are made to the extent of 24 million pounds (nearly 11 million kilograms) per year throughout the world. Nicotinic acid (pyridine-3-caiboxylic acid), also called niacin, has many uses. See also Niacin. Nicotinic acid is made by the oxidation of 3-picolme or 2-mcthyl-5-cthylpyridine (the isocinchomcnc acid produced is partially deearboxylated). Alternatively, quinoline (the intermediate quinolinic acid) is partially deearboxylated with sulfuric add in the presence of selenium dioxide at about 300° C or with nitric acid, or by electrochemical oxidation. Nicotinic acid also can be made from 3-picoline by catalytic ammoxidation to 3-cyanopyridine, followed by hydrolysis. 

Pteridine-4-caiboxylic acid, 2-amino-ethyl ester, 3, 277... 

CN [6/f-[3(Z),6a,7p(Z)]]-7-[[(2-amino-4-thiazolyl)(methoxyi mi no)acetyl]amino]-3-[2-(4-methyl-5-thiazolyl)ethenyl]-8-oxo-5-thia-1 -a7.abicyclo[4.2.0]oct-2-ene-2-caiboxylic acid (2,2-dimethyl-1-oxopropoxy)methyl ester... 

Cyclocondensation routes also provide access to pyrimidines. 2,3-Disubstituted pyrido[2,3-/i]-quinazolin-4(3//)-ones are obtained via cyclocondensation of 5-aminoquinoline-6-caiboxylic acid with acid chlorides <02SC235>. 5,6,8-Trialkyl-7-methoxy-2-aminoquinazolines are obtained from 1,3-dimethoxybenzenes via cyclocondensation of intermediate dihydrobenzenes with guanidine carbonate <02TL3295>. Diastereoselective intramolecular hetero Diels-Alder cyclization of a pyrazole carboxaldehyde condensed onto 1,3-dimethylbarbituric acid (101) gave polycyclic heterocycle 102 <02T531>. An efficient one-step synthesis of cyclobutene-annelated pyrimidinones 103 from methyl 2-chloro-2-cyclopropylideneacetate and amidines has been... 

Poly(caiboxylic acid)s Quaternized poly(4-(or 2-)vinyl pyridine) 144-149 ... 

The phenyl group became a practical protective group for carboxylic acids when Sharpless published a mild, effective one-step method for its conversion to a carboxylic acid.1 It has recently been used in a synthesis of the amino acid statine, where it served as a masked or caiboxylic acid equivalent.2... 

Caiboxylic acids, tetrahedral intermediates derived from, spectroscopic detection and investigation of their properties, 21, 37... 

The tetrahedral intermediate T can eliminate any one of the three -OH groups to reform either the original carboxylic acid or labeled caiboxylic acid. Further reaction of water with mono-labeled carboxylic acid leads to the doubly labeled product. 

Oxidation of primary alcdiols to aldehydes using these oxidants does not result in overoxidation to caiboxylic acids, in contrast to many other oxidants. This arises since the aldehydes are foimed under anhydrous conditions and are not capable of hydration, which is a necessary requirement for conversion to a carboxylic acid. 

Step S. Stieti Caiboxylic Acid from the Cfoitps menu. 

The Kharasch-Sosnovsky reaction may be carried out in the presence of caiboxylic acids to introduce the acyloxy moiety of the acid used, and may also be conducted photochemically at room temperature using UV irradiation. Peroxy acids, diacyl peroxides, and peroxyphosphates and peroxyphospho-nates are alternative oxidants. r-Butyl hy operoxide may also be used in place of peroxy esters with broadly similar results, although formations of mixed peroxides and r-butyl ethers can then compete with allyl ester production. 

Simple alcohols can be obtained from the decomposition of peroxy acids in cyclohexane or boizene at reflux. This chain reaction, which is efficient for adamantane-l-caiboxylic acid (equation 40), is unfortunately usually complicated by side reactions involving hydrogen abstraction firom the substrate or solvent. ... 

---