Methanol → 4-(3-Amino-2-hydroxy-phenyl)-thiophene-2-carboxylic acid hydrobromide

HRID 238716Notes

Reaction equation

HRID 238716 reaction equation
Br.[NH2:2][C:3]1[C:4]([O:17]C)=[C:5]([C:9]2[CH:10]=[C:11]([C:14]([OH:16])=[O:15])[S:12][CH:13]=2)[CH:6]=[CH:7][CH:8]=1.B(Br)(Br)[Br:20].CO>ClCCl>[BrH:20].[NH2:2][C:3]1[C:4]([OH:17])=[C:5]([C:9]2[CH:10]=[C:11]([C:14]([OH:16])=[O:15])[S:12][CH:13]=2)[CH:6]=[CH:7][CH:8]=1

Participants

5

Reactant 3

HCID 887MethanolHCID 25134Boron tribromideHCID 574838484-(3-Amino-2-methoxy-phenyl)-thiophene-2-carboxylic acid hydrobromide

Product 1

HCID 574838464-(3-Amino-2-hydroxy-phenyl)-thiophene-2-carboxylic acid hydrobromideYield 17.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-(3-Amino-2-methoxy-phenyl)-thiophene-2-carboxylic acid hydrobromide 19b (360 mg, 1.45 mmol) was dissolved in 5 mL of dichloromethane followed by dropwise addition of boron tribromide (2.8 mL, 5.6 mmol). The reaction mixture was reacted at room temperature for 4.5 hours. The reaction mixture was added with 5 mL of methanol and concentrated under reduced pressure. The residue was diluted with 10 mL of ethyl acetate and stirred for 0.5 hours. The mixture was filtered and the filter cake was dried to obtain the title compound 4-(3-amino-2-hydroxy-phenyl)-thiophene-2-carboxylic acid hydrobromide 19c (80 mg, yield 17.5%) as a grey solid.

Workup

  1. customThe reaction mixture was reacted at room temperature for 4.5 hours
  2. concentrationconcentrated under reduced pressure
  3. additionThe residue was diluted with 10 mL of ethyl acetate
  4. filtrationThe mixture was filtered
  5. customthe filter cake was dried

Sources & evidence

ORD record
ord-ebac0666daf9434a81a06d62d0848ec7
Source dataset
uspto-grants-2014_02
Patent number
US08642637B2

Reaction notes

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