Methane → 2-Amino-5-isopropyl-thiophene-3-carboxylic acid

HRID 1974964Notes

Reaction equation

HRID 1974964 reaction equation
[NH2:1][C:2]1[S:3][C:4]([CH:11]([CH3:13])[CH3:12])=[CH:5][C:6]=1[C:7]([O:9]C)=[O:8].C>[OH-].[Na+].C(O)C>[NH2:1][C:2]1[S:3][C:4]([CH:11]([CH3:13])[CH3:12])=[CH:5][C:6]=1[C:7]([OH:9])=[O:8]

Participants

5

Reactant 2

HCID 297MethaneHCID 2756462HCID 2756462, compound

Product 1

HCID 150855502-Amino-5-isopropyl-thiophene-3-carboxylic acidYield 70.2%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 14798Sodium HydroxideSolvent

Procedure

Methyl 2-amino-5-isopropylthiophene-3-carboxylate (59.8 g, 0.3 mol) was dissolved in 210 ml of 50% aqueous ethanol containing 24.6 g (0.6 mol) of sodium hydroxide and refluxed overnight. The ethanol was evaporated in vacuo, and the aqueous solution was extracted twice with chloroform. The aqueous phase was acidified by adjusting the pH to 4.5 with hydrochloric acid. The precipitate was isolated, dissolved in 150 ml of ethanol, and treated with 4 g of charcoal (Norit SU18). The mixture was filtered and concentrated to 100 ml. Water (500 ml) was added and the precipitate was filtered off to yield 39 g (70%) of 2-amino-5-isopropylthiophene-3-carboxylic acid melting with decomposition at 115° C. 1H-NMR (CDCl3, δ) : 1.2 (d, 6H), 2.9 (m, 1H), 5.8 (broad, 2H), 6.65 (s, 1H).

Workup

  1. temperaturerefluxed overnight
  2. customThe ethanol was evaporated in vacuo
  3. extractionthe aqueous solution was extracted twice with chloroform
  4. customThe precipitate was isolated
  5. filtrationThe mixture was filtered
  6. concentrationconcentrated to 100 ml
  7. additionWater (500 ml) was added
  8. filtrationthe precipitate was filtered off

Sources & evidence

ORD record
ord-9e80babb02584e379aab56c705982d20
Source dataset
uspto-grants-1994_02
Patent number
US05284847

Reaction notes

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