Hydrochloric Acid → 6-Amino-5-bromobenzofuran-3-carboxylic acid

HRID 595636Notes

Reaction equation

HRID 595636 reaction equation
[NH2:1][C:2]1[C:15]([Br:16])=[CH:14][C:5]2[C:6]([C:9]([O:11]CC)=[O:10])=[CH:7][O:8][C:4]=2[CH:3]=1.O[Li].O.Cl>O1CCOCC1.O>[NH2:1][C:2]1[C:15]([Br:16])=[CH:14][C:5]2[C:6]([C:9]([OH:11])=[O:10])=[CH:7][O:8][C:4]=2[CH:3]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 168937Lithium hydroxide, monohydrateHCID 89428742Ethyl 6-amino-5-bromobenzofuran-3-carboxylate

Product 1

HCID 903324196-Amino-5-bromobenzofuran-3-carboxylic acidYield 97.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 312751,4-DioxaneSolvent

Procedure

To a solution of ethyl 6-amino-5-bromobenzofuran-3-carboxylate (58 g, 204 mmol) in 1,4-dioxane and H2O (850 mL and 150 mL) was add LiOH.H2O (42.8 g, 1.02 mol). The reaction mixture was refluxed for 2 hours, and then 400 mL H2O was added to the reaction mixture. After acidifying to pH 4˜5 with HCl, the resulting solid was filtered to give the product of 6-amino-5-bromobenzofuran-3-carboxylic acid (51 g, yield: 97%). 1H-NMR (DMSO-d6, 400 MHz) δ 8.36 (s, 1H), 7.87 (s, 1H), 7.02 (s, 1H), 5.51 (br s, 2H). MS (M+H)+: 256/258.

Workup

  1. temperatureThe reaction mixture was refluxed for 2 hours
  2. filtrationthe resulting solid was filtered

Sources & evidence

ORD record
ord-e0ff6934380142d0abdfa42968bbc27d
Source dataset
uspto-grants-2016_01
Patent number
US09243002B2

Reaction notes

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