Caiboxylic acids derivatives

The amination of the a-carbon atom of caiboxylic acid derivatives has been extensively studied by Ef-fenberger and cowoikers. Ethyl (5)-a-bromopropionate reacted with (/ )- -phenylethylamine to give (2RXR)- and (25,r )-/V-(l -phenylethyl)alanine ethyl ester, e.g. (2/ ,l / )-(4) and (2S,l / )-(4). Prolonged reaction time afforded the products in higher yields with decreasing stereospecificity (Scheme 5). 

Scheme 3.50 Synthesis and cyclization of iV-(2-nitrophenyl)pyiiolidine-2-caiboxylic acid derivatives...

KOLBE - SCHMIDT Salicylic Acid Synthesis Caiboxylation (usually ortho) of phenols. Industrial method to obtain salicylic acid derivatives... 

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. 

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

Nitriles can also be named as derivatives of carboxylic acids by replacing the -ic acid or -ok acid ending with -onitrile, or by replacing the -caiboxylic acid ending with -carbonitrile. The nitrile carbon atom is attached to Cl but is not itself numbered. 

This type of stereocontrol is featured in a synthesis of the fungitoxin ( )-chokol-A (156) (Scheme 32). Alcohol (147) (easily prepared from 1-hexen-S-one in two steps) efficiently gave the allyl chloride (1 ) (CCWPBus). Tlie metallation/cyclization/oxidation step (148) - (149) - (150) - (151) (described in detail) furnished ds-cyclopentylmethanol (151) (64% from 148 together with 2% of its trans epimer and 6% of a positional isomer derived from 141) which was oxidized to ds-caiboxylic acid (152). lodolactonizationAeduction (152) (153) -4 (154) secured the desired cis disposition of the r-hy-... 

Esters are carboxylic acid derivatives in which the hydroxyl group (—OH) is replaced by an alkoxy group (—OR). An ester is a combination of a caiboxylic acid and an alcohol, with loss of a molecule of water. We have seen that esters can be formed by the Fischer esterification of an acid with an alcohol (Section 20-10). 

Other Derivatives of SaUcylic Acid. p-Aminosalicylic acid and its salts have been used in the treatment of tuberculosis. / -Aminosalicylic add can be prepared by the caiboxylation of in-amiuoplienol. Metliylene-5,5-disalicylic acid, produced by heating two parts salicylic acid with 1-1.5 parts of 30-40 wt % formaldehyde in the presence of an add catalyst, is used as an intermediate in the production of bacitracin me thy le ne di salicy la te. 

Uncertainties in identifying specific functional groups results in a range of n. The lower limit considers all aromatic carbon to be nonprotonated, the oxygen-substituted carbon to be a tertiary ether, the caiboxylate to be an ester, and the carbonyl to be a ketone. The upper limit is derived by assuming that all the aromatic carbon is protonated, the oxygen-substituted carbon is a primary alcohol, and the carboxylate is an acid. 

Frost, J.W., Miermont, A., Schweitzer, D. and Bui, V. (2010) Novel terephtheilic and trimeUitic based acids and caiboxylate derivatives thereof, W02010148081. 

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