Potassium Hydroxide → 2-Thiophenecarboxylic acid, 4-bromo-3-methoxy-

HRID 1058548Notes

Reaction equation

HRID 1058548 reaction equation
[Br:1][C:2]1[C:3]([O:11][CH3:12])=[C:4]([C:7]([O:9]C)=[O:8])[S:5][CH:6]=1.[OH-].[K+]>CO.O>[Br:1][C:2]1[C:3]([O:11][CH3:12])=[C:4]([C:7]([OH:9])=[O:8])[S:5][CH:6]=1

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 2736824Methyl 4-bromo-3-methoxythiophene-2-carboxylate

Product 1

HCID 5422672-Thiophenecarboxylic acid, 4-bromo-3-methoxy-Yield 95.6%

Reagents, catalysts & solvents 2

HCID 887MethanolSolvent2×HCID 962WaterSolvent

Procedure

A solution of 37.5 g (0.15 mole) of methyl 4-bromo-3-methoxy-2-thiophenecarboxylate and 12 g of KOH (0.18 mole) in a mixture of 250 mL of methanol and 100 mL of water was refluxed for 2 hr. The reaction mixture was cooled and most of the methanol was removed in vacuo. The solution was partitioned with ether and dilute aqueous HCl. The organic phase was separated dried over MgSO4, filtered and concentrated and dried under a vacuum to give 34 g (94%) of a colorless solid. mp 191-192° C. 1H NMR (300 MHz, CDCl3): δ 7.5 (s, 1H); 4.1 (s, 3H). Anal. Calc'd for C6H5BrO3S: C, 30.04; H, 2.23; S, 13.52. Found: C, 29.89; H, 2.06; S, 13.14.

Workup

  1. temperaturewas refluxed for 2 hr
  2. customwas removed in vacuo
  3. customThe solution was partitioned with ether and dilute aqueous HCl
  4. customThe organic phase was separated
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customdried under a vacuum

Sources & evidence

ORD record
ord-503f48f7f89f429582518edbcc2e6109
Source dataset
uspto-grants-2003_02
Patent number
US06518222B2

Reaction notes

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