Salicylic acid carboxyl

Originally isolated and characterized from the petals of Clarkia breweri, salicylic acid carboxyl methyltransferase (SAMT), converts salicylic acid to methylsalicylate.14 Methysalicylate, a volatile ester, has a characteristic wintergreen scent Apart from its putative role in defense, methylsalicylate is an important chemoattractant for moth-pollinated flowers and one of the main volatiles released from Clarkia breweri flowers.44,55 SAMT is a member of the type 3 family of plant MTs. Similarly to the previously discussed families of methyltransferases, type 3 MTs are homodimeric proteins. 

ROSS, J.R., NAM, K.H., D AURIA, J.C., PICHERSKY, E., S-Adenosyl-L-methionine salicylic acid carboxyl methyltransferase, an enzyme involved in floral scent production and plant defense, represents a new class of plant methyltransferases, Arch. Biochem. Biophys., 1999,367,9-16. 

RhB-COOH, TPP(C0CI)4 and ZnTPP(COOH)4 Benzene derivatives benzoic, phthalic or salicylic acid Carboxylate-terminated dimeric viologen Mc2 merocyanine acid... 

BSMT benzoic acid/salicylic acid carboxyl methyltransferase... 

When the phenol contains a carboxylic acid group, e.g., m- or p-hydroxy-benzoic acid, the acetylated derivative will of course remain in solution as the sodium salt, but is precipitated when the solution is subsequently acidified. Salicylic acid, however, cannot be acetylated under these conditions. 

Salicylic acid. The preparation of salicylic acid by passing carbon dioxide into dry sodium phenoxide at 170-190° is the classical example of the Kolbe-Schmltt reaction. The latter is a method for introducing a carboxyl group directly into a phenol nucleus. 

This difference in behavior for acetic acid in pure water versus water buffered at pH = 7 0 has some important practical consequences Biochemists usually do not talk about acetic acid (or lactic acid or salicylic acid etc) They talk about acetate (and lac tate and salicylate) Why Its because biochemists are concerned with carboxylic acids as they exist in di lute aqueous solution at what is called biological pH Biological fluids are naturally buffered The pH of blood for example is maintained at 7 2 and at this pH carboxylic acids are almost entirely converted to their carboxylate anions... 

Section 24 10 The Kolbe-Schmitt synthesis of salicylic acid is a vital step m the preparation of aspirin Phenols as their sodium salts undergo highly regioselective ortho carboxylation on treatment with carbon dioxide at elevated temperature and pressure... 

Manufacture. Several methods have been described for the preparation of -hydroxyben2oic acid. The commercial technique is similar to that of salicylic acid, ie, Kolbe-Schmitt carboxylation of phenol. The modification includes the use of potassium hydroxide in place of caustic (51). The dried potassium phenate is heated under pressure, 270 kPa (2.7 atm) or more, with dry carbon dioxide at 180—250°C. The potassium salt [16782-08-4] of Nhydroxyben2oic acid forms almost quantitatively and can be converted to free acid by using a mineral acid. 

Hydrolysis of aspirin in H2 0 leads to no incorporation of into the product salicylic acid, ruling out the anhydride as an intermediate and thereby excluding mechanism 1. The general acid catalysis of mechanism III can be ruled out on the basis of failure of other nucleophiles to show evidence for general acid catalysis by the neighboring carboxylic acid group. Because there is no reason to believe hydroxide should be special in this way, mechanism III is eliminated. Thus, mechanism II, general base catalysis of hydroxide-ion attack, is believed to be the correct description of the hydrolysis of aspirin. 

Bromophenol blue (3.0...4.6) aliphatic carboxylic acids [225 — 228] malonic and lactic acids [229] palmitic and lactic acids [230] malonic, glycolic, malic, citric, tartaric, ketoglutaric, galacturonic and oxalic acids [196] dicarboxylic acids, succinic acid [231] indoleacetic acid, trichloroacetic acid [232] palmitic acid, palmityl- and stearyllactic acid [223] benzoic, sorbic and salicylic acid [234] metabolites of ascorbic acid [235] chloropropionic acid [236] oligogalacturonic acids [237] amino acids, hydrocarbons, mono-, di- and triglycerides [238] xylobiose, xylose, glucose and derivatives [239] sugar alcohols [91] toxaphene [240]... 

Detection and result The chromatogram was freed from mobile phase and immersed for 3 s in the dipping solution and heated to 125°C for 5 — 10 min. The carboxylic acids terephthalic acid (tiRi 5), succinic acid (fiRi 50 — 55), phthalic acid (hRf 55 — 60), suberic acid (tiRi 60 — 65), sebacic acid (fiRi 65 — 70), benzoic acid (tiRi 75 — 80) and salicylic acid (hRf 80 — 85) yielded brown zones on a light brown background. The detection limit was 2 pg acid per chromatogram zone. 

Fig. 1 Separation of carboxylic acids (schematic representation). Citric acid (1), lactic acid (2), phthalic acid (3), sebacinic acid (4), salicylic acid (5), mixture (M).

Bromomethyl-3-methylquinoxaline (273) and m-hydroxybenzoic acid (274) gave either 2-(m-hydroxybenzoyloxymethyl)-3-methylquinoxaline (275) [KOH (1 mol), EtOH, reflux, 2h 69%] or 2-(m-carboxyphenoxymethyl)-3-methylquinoxaline (276) [KOH (2 mol), EtOH, 50°C—>reflux, 1 h 44%] p-hydroxybenzoic acid reacted similarly but o-hydroxybenzoic acid (salicylic acid) gave only the isomer of product (275) even in the presence of KOH (2 mol). It would seem that the substrate (275) preferred to react at the phenolic anion rather than at the carboxylate anion when both were present... 

The complexes of aromatic hydroxy carboxylic acids (salicylic acid and its isomers) with [Bu2Sn(IV)] and [Ph3Sn(IV)] were obtained. The FT-IR and Raman spectra clearly demonstrated that the organotin(IV) moieties react with the O, O) atoms of the ligands. It was found that in most cases the -COO group chelated to the central atoms, but monodentate coordination was also observed. The complexes probably have polymeric structures. 

The effect of temperature on acid or base pKa values cannot be reliably predicted [2, 17, 23]. For many nitrogenous bases, the pKa decreases by 0.1-0.3 for every 10 °C rise in temperature. For some carboxylic acids (e.g. acetic, benzoic, salicylic acids), the pKj remains essentially unchanged between 25 and 37°C. 

It is worth noting that the Ullmann-Goldberg condensation of aryl halides with phenols and anilines worked efficiently in the presence of copper in water.50 For example, the coupling of 2-chlorobenzoic acid with 4-chlorophenol (K2C03/pyridine/copper powder) gave 2-(4-chlorophenoxy)carboxylic acid (Eq. 6.23).51 The Cu(I)-catalyzed transformation of 2-bromobenzoic acid into salicylic acid has also been studied in aqueous media (Eq. 6.24).52... 

Salicylic acid (Fig. 13.4.2) is an example of a carboxylic acid with the general formula R-COOH. In this class of organic compounds the carbonyl functionality... 

Good non-colored negative charging CCAs have been obtained by making non-colored analogues of the 2 1 chromium complex azo dyes. This is achieved by making the metal complex of an aromatic ortho-hydroxy carboxylic acid. Typical examples are the chromium, aluminum, and zinc complexes of di-tert-butyl salicylic acid, e.g., BONTRON E-8136 41 (53) and BON-acid36,41,42 e.g., BONTRON E-82 (54). 

Despite the many simple methods for preparation of carboxylic esters and thioesters, in some instances, use of 1-acylbenzotriazoles 915 as O and S acylating agents may be advantageous. For example, easy to prepare salicylic acid derivative 941 reacts with cyclopentanol under microwave irradiation to give 92% yield of cyclopentyl salicylate in 10 min <2006JOC3364>. In another example, L-phenylalanine derivative 942 reacts with benzyl mercaptan... 

Replacement of the hydroxyl group on the phenyl ring with a carboxyl group forms a molecule of benzoic acid. Addition of a hydroxyl at the 2-position on a benzoic acid molecule forms 2-hydroxybenzoic acid or salicylic acid. The slightly more complex phenylpropanoid skeleton contains a linear three-carbon chain (the propanoic group) added to the benzene ring (the phenyl group). Addition of ammonia to carbon 2 of this three-carbon side chain yields the amino acid phenylalanine (Fig. 3.3). Phenylalanine... 

Aspirin, also known as acetylsalicylic acid (ASA), can be synthesized when the carboxyl group in acetic acid (----COOH) reacts with the (--------OH group in the salicylic acid molecule ... 

Carboxylic acid group, in salicylic acid reactions, 22 2-4... 

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