Topic
Carboxylic acid
About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.
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TL;DR: Pyridines and pyrazines substituted with 1,2,4-oxadiazole-5-ones, 1, 2, 4-oxathiazoline-2-ones and 1, 3, 4 -oxanthioxymethyl derivatives of isosteres were also prepared in order to increase their lipophilicity and therefore improve their cellular permeability as discussed by the authors.
Abstract: Pyridines and pyrazines substituted with 1,2,4-oxadiazole-5-ones, 1,2,4-oxadiazole-5-thiones, and 1,3,4-oxathiazoline-2-ones were synthesized and tested against Mycobacterium tuberculosis. The two former ring systems were documented in the literature to act as carboxylic acid isosteres. The latter series was synthesized as possible synthetic intermediates to 1,2,4-thiadiazole-3-ones and was included in this study due to their interesting activity. Pivaloyloxymethyl derivatives of the isosteres were also prepared in order to increase their lipophilicity and therefore improve their cellular permeability. The derivatized isosteres were expected to be biotransformed by esterases to the active species after penetration of the mycobacterial cell wall. Biological properties of the compounds were compared with the unmodified polar isosteres of pyrazinoic and nicotinic acids. The majority of the compounds exhibited activities ranging from 0.5 to 16 times the potency of pyrazinamide.
110 citations
TL;DR: Curtius rearrangement of the resulting carboxylic acid provided the enantiopure benzyloxycarbonyl (Cbz)-protected β-amino esters 6 in good yields (74−79%).
Abstract: A general procedure for the synthesis of enantiopure β-substituted, β-amino acids is presented. Alkylation of the sodium enolates derived from chiral N-acyloxazolidinone imides 2 (R = Me, i-Pr, t-Bu, Ph, Bn) with tert-butyl bromoacetate afforded the 2-substituted succinate derivatives 3 in good yields (82−89%) and with high selectivity (≥93:7). Following hydrolysis, Curtius rearrangement of the resulting carboxylic acid provided the enantiopure benzyloxycarbonyl (Cbz)-protected β-amino esters 6 in good yields (74−79%).
110 citations
TL;DR: In this article, NaOH is added to a mixture of 4-bromo-3-methylaniline, 4-chlorobutyryl chloride, and catalytic TBAC in THF/H2O.
110 citations
TL;DR: In this paper, a one-pot preparation of t-butyl esters and ethers is described that proceeds from the carboxylic acid or alcohol and tbutanol using only anhydrous magnesium sulfate and catalytic sulfuric acid as additional reagents.
110 citations
TL;DR: Covalent linking of glucosamine to the functionalized surface was achieved using carbodiimide chemistry verifying that the modified substrates are suitable for biomolecule attachment.
110 citations