ChemicalBook CAS DataBase List 5-HYDROXY-1-BENZOFURAN-2-CARBOXYLIC ACID

5-HYDROXY-1-BENZOFURAN-2-CARBOXYLIC ACID synthesis

9synthesis methods

Product Name:5-HYDROXY-1-BENZOFURAN-2-CARBOXYLIC ACID
CAS Number:56172-36-2
Molecular formula:C9H6O4
Molecular Weight:178.14

10242-08-7
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$18.00/250mg

5-HYDROXY-1-BENZOFURAN-2-CARBOXYLIC ACID

56172-36-2
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$45.00/100mg

Yield:56172-36-2 100%

Reaction Conditions:

with boron tribromide in dichloromethane at -78 - 20; for 4 h;

Steps:

1.1 Preparation of 4.6-dibromo-2-carboxy-5-hydroxybenzofuran

Step 1: Preparation of 2-carboxy-5-hydroxybenzofuran. 2-Carboxy-5-methoxybenzofuran (1.0 g, 5.2 mmol) was dissolved in anhydrous dichloromethane (25 ml) and cooled to -78° C. A 1 M solution of borontribromide (15.6 ml) in dichloromethane was added slowly. The reaction mixture was allowed to warm to ambient temperature under an atmosphere of nitrogen, and stirred 4 hours. The solution was quenched with aqueous ammonium chloride (20 ml) and extracted with ethyl acetate. The aqueous layer was washed with water and dried over sodium sulfate. 0.9 g (100%) of crude product was obtained. ¹H NMR(CD₃OD) δ=6.84 (dd, 1H), 6.95 (d, 1H), 7.17 (s, 1H), 7.32 (d, 1H).

References:

US2005/26969,2005,A1 Location in patent:Page/Page column 12