2,5-дигидроксибензойной кислоты

Описание

Gentisic acid is a dihydroxy benzoic acid. It is a derivative of benzoic acid and a minor (1 %) product of the metabolic break down of aspirin, excreted by the kidneys.
It is also found in the African tree Alchornea cordifolia and in wine.

Химические свойства

White to light beige crystalline powder. 2,5-Dihydroxybenzoic Acid [490-79-9] (gentisic acid, 2,5-DHBA), C7H6O4, Mr 154.1, mp 205 C, is soluble in water and alcohols but insoluble in benzene and chloroform. The acid is stable in boiling water and gives a deep blue color with iron(III) chloride. Here, the acid decomposes to form p-benzoquinone [106-51-4] and carbon dioxide. 2–5-Dihydroxybenzoic acid is used as an antirheumatic drug and, more recently, as a color developer for thermal paper.

Использование

2,5-dihydroxybenzoic acid are?used as intermediates for pharmaceuticals (especially for antipyetic anlgesic, antirheumatism) and other organic synthesis. They are used as matrix for ionization of peptides, proteins and carbohydrates. In industrial field, they are?used as intermediates for the production of other organic chemicals, resins, polyesters, plasticizers, dyestuffs, preservatives, and rubber chemicals.

прикладной

As a hydroquinone , gentisic acid is readily oxidized and is used as an antioxidant excipient in some pharmaceutical preparations. In the laboratory, it is used as a sample matrix in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry , and has been shown to conveniently detect peptides incorporating the boronic acid moiety by MALDI .

Определение

ChEBI: A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions.

Методы производства

Gentisic acid is produced by carboxylation of hydroquinone.
C₆H₄(OH)₂ + CO2 → C₆H₃(CO₂H)(OH)₂
This conversion is an example of a Kolbe–Schmitt reaction.

Общее описание

Aspirin metabolite.

Профиль безопасности

Poison bp intravenous route. Moderately toxic by ingestion and intraperitoneal routes. Experimental teratogenic and reproductive effects. Mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.

Методы очистки

Crystallise gentisic acid from hot water or *benzene/acetone. Dry it in a vacuum desiccator over silica gel. [Beilstein 10 H 384, 10 IV 1441.]