ChemicalBook CAS DataBase List 4-Bromo-2-hydroxybenzoic acid

4-Bromo-2-hydroxybenzoic acid synthesis

13synthesis methods

Product Name:4-Bromo-2-hydroxybenzoic acid
CAS Number:1666-28-0
Molecular formula:C7H5BrO3
Molecular Weight:217.02

Under nitrogen atmosphere, add copper (II) bromide (8.8 g, 39.4 mmol, 1.2 equivalents), acetonitrile (50 ml), and 4-aminosalicylic acid (5.1 g, 49.5 mmol) to the vacuum-dried reaction flask, 1.5 equivalent). The reaction mixture was cooled to 0°C, and 2-hydroxy-4-bromobenzoic acid precursor (5.0 g, 32.6 mmol, 1.0 equiv) was added portion-wise. Additional acetonitrile (25 mL) was added to the mixture and stirred at 0 °C for 2 h. The organic extracts were combined and washed with 20% aqueous hydrochloric acid, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was dissolved in diethyl ether, and the resulting solution was extracted with 15% sodium hydroxide aqueous solution. The aqueous solution was washed with diethyl ether, acidified to pH 1 with 6N hydrochloric acid aqueous solution, and the mixture was extracted with diethyl ether. The combined organic extracts were washed with brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was treated with chloroform, and the precipitate collected by filtration was 4-Bromo-2-hydroxybenzoic acid.

99-06-9
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1666-28-0
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$9.00/1g

Yield:1666-28-0 100%

Reaction Conditions:

with sulfuric acid;bromine in acetic acid

Steps:

I.92 [5-(4-Bromo-3-methoxy-phenyl)-3-methyl-2,3-dihydro-[1,3,4]thiadiazol-2-yl]-cyclohexyl-amine
[5-(4-Bromo-3-methoxy-phenyl)-3-methyl-2,3-dihydro-[1,3,4]thiadiazol-2-yl]-cyclohexyl-amine To a mixture of 3-hydroxybenzoic acid (14.480 mmol, 2 g) in acetic acid (14.5 mL) and sulfuric acid (1.5 mL) at 50° C., a solution of bromine (15.204 mmol, 0.780 mL) in acetic acid (7.2 mL) was added and stirred 30 minutes at 100° C. The reaction was allowed to cool to RT and diluted with water. The aqueous layer was extracted with ethyl acetate, washed with water and brine, dried (MgSO₄), filtered, and concentrated under reduced pressure to give the 4-bromo-2-hydroxy-benzoic acid. Yield: 100%.

References:

Vergne, Fabrice;Ducrot, Pierre;Andrianjara, Charles;Bernardelli, Patrick;Lorthois, Edwige US2003/45557, 2003, A1

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65-49-6 Synthesis