Hydrochloric Acid → 4-Bromo-3-hydroxythiophene-2-carboxylic acid

HRID 644464Notes

Reaction equation

HRID 644464 reaction equation
C[O:2][C:3]([C:5]1[S:6][CH:7]=[C:8]([Br:10])[CH:9]=1)=[O:4].[OH-:11].[Na+].CO.O.Cl>C(OCC)(=O)C>[Br:10][C:8]1[C:9]([OH:11])=[C:5]([C:3]([OH:2])=[O:4])[S:6][CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 12752071Methyl 4-bromothiophene-2-carboxylateHCID 22242641Methanol--water (1/1)

Product 1

HCID 546892204-Bromo-3-hydroxythiophene-2-carboxylic acidYield 69.6%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A mixture of 4-bromothiophene-2-carboxylic acid methyl ester (500 mg, 2.1 mmol), sodium hydroxide (261 mg, 6.3 mmol) in a mixed solvent of methanol/water (2.5 mL+2.5 mL) was refluxed for 2 hours. After the reaction mixture was cooled to room temperature, 2N hydrochloric acid was added to adjust pH to 1, and it was diluted with ethyl acetate. After the ethyl acetate layer was washed successively with water and brine, dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure to give the title compound (326 mg, 69.4%) as a red brown powder.

Workup

  1. temperaturewas refluxed for 2 hours
  2. washAfter the ethyl acetate layer was washed successively with water and brine
  3. dry with materialdried over anhydrous sodium sulfate
  4. customthe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-8a831adb7e99444fbb317ac244e8b715
Source dataset
uspto-grants-2010_04
Patent number
US07700655B2

Reaction notes

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