Hydrochloric Acid → 5-Ethynylthiophene-2-carboxylic acid

HRID 499794Notes

Reaction equation

HRID 499794 reaction equation
C[Si](C)(C)[C:3]#[C:4][C:5]1[S:9][C:8]([C:10]([O:12]CC)=[O:11])=[CH:7][CH:6]=1.[Li+].[OH-].O.Cl>C1COCC1>[C:4]([C:5]1[S:9][C:8]([C:10]([OH:12])=[O:11])=[CH:7][CH:6]=1)#[CH:3]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 3939Lithium HydroxideHCID 66974178Ethyl 5-(2-trimethylsilyl-ethyn-1-yl)-thiophene-2-carboxylate

Product 1

HCID 450847505-Ethynylthiophene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
40 °C

Procedure

To a solution of ethyl 5-(2-trimethylsilyl-ethyn-1-yl)-thiophene-2-carboxylate prepared above (529 mg, 2.10 mmol) in THF (20 mL), 1N aq. LiOH (7.0 mL, 7.0 mmol) was added. After the mixture was stirred at 40° C. overnight, it was poured into water. The aqueous solution was acidified with 1N HCl to pH 1. The product was extracted with EtOAc. The EtOAc solution was washed with brine, dried over MgSO4, concentrated in vacuo to give 5-ethynyl-thiophene-2-carboxylic acid (316 mg). MS 153 (M+H).

Workup

  1. extractionThe product was extracted with EtOAc
  2. washThe EtOAc solution was washed with brine
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-c905c3574124465c9e85da3f6fc0ab1b
Source dataset
uspto-grants-2010_08
Patent number
US07767697B2

Reaction notes

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