Barium Carbonate → 4-Hydroxyimino-tetrahydro-thiophene-3-carboxylic acid methyl ester

HRID 902506Notes

Reaction equation

HRID 902506 reaction equation
[CH3:1][O:2][C:3]([CH:5]1[C:9](=O)[CH2:8][S:7][CH2:6]1)=[O:4].Cl.[NH2:12][OH:13].C(=O)([O-])[O-].[Ba+2]>CO>[CH3:1][O:2][C:3]([CH:5]1[C:9](=[N:12][OH:13])[CH2:8][S:7][CH2:6]1)=[O:4]

Participants

5

Reactant 3

HCID 10563Barium CarbonateHCID 984243-Thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl esterHCID 443297Hydroxyamine hydrochloride

Product 1

HCID 736752764-Hydroxyimino-tetrahydro-thiophene-3-carboxylic acid methyl esterYield 98.5%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A suspension of 4-oxo-tetrahydro-thiophene-3-carboxylic acid methyl ester (33) (16.96 g, 106 mmol), hydroxylamine hydrochloride (16.96 g, 244 mmol) and barium carbonate (48.16 g, 244 mmol) in methanol (800 mL) was refluxed overnight. The solution was cooled and filtered. The filtrate was concentrated in vacuo. The residue was suspended in water and extracted by ethyl acetate. The combined organic phase was dried over MgSO4 and concentrated to yield 18.30 g (98%) of an isomeric mixture of 4-hydroxyimino-tetrahydro-thiophene-3-carboxylic acid methyl ester as a viscous oil. 1H NMR (400 MHz, CDCl3) δ 3.14-4.11 (m, 7H), 8.17 (m, 1H) ppm. The isomeric mixture was used in the following step without further purification.

Workup

  1. temperaturewas refluxed overnight
  2. temperatureThe solution was cooled
  3. filtrationfiltered
  4. concentrationThe filtrate was concentrated in vacuo
  5. extractionextracted by ethyl acetate
  6. dry with materialThe combined organic phase was dried over MgSO4
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-8a8344aabffa4d6f8f6d6c84987d3e90
Source dataset
uspto-grants-2008_04
Patent number
US07365200B2

Reaction notes

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