Stannous chloride dihydrate → Methyl 7-amino-1-benzothiophene-2-carboxylate

HRID 1986662Notes

Reaction equation

HRID 1986662 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[C:10]([N+:14]([O-])=O)=[CH:11][CH:12]=[CH:13][C:7]=2[CH:6]=1)=[O:4].O.O.Cl[Sn]Cl>C(O)(=O)C.Cl>[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[C:10]([NH2:14])=[CH:11][CH:12]=[CH:13][C:7]=2[CH:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 61436Stannous chloride dihydrateHCID 57722418Methyl 7-nitrobenzo[b]thiophene-2-carboxylate

Product 1

HCID 45089769Methyl 7-amino-1-benzothiophene-2-carboxylateYield 100%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 313Hydrochloric AcidSolvent

Procedure

To a mixture of 7-nitro-benzo[b]thiophene-2-carboxylic acid methyl ester (100 mg) in acetic acid (4 mL) was added a solution of SnCl2.2H2O (10 eq) in 1.5 mL of concentrated HCl. The reaction was stirred at room temperature 12 h. The excess acid was partially removed in vacuo, and the reaction mixture was then poured into a flask (250 mL) and was neutralized with saturated NaHCO3 solution at 0° C. The pH was brought up to pH 9 by adding solid NaHCO3. The resulting aqueous mixture was diluted with EtOAc, and the Tin-by product was removed by filtering through a pad of diatomaceous earth. The pad was rinsed with EtOAc and the combined filtrates were partitioned in a separatory funnel. The aqueous layer was extracted with EtOAc two times. The combined organics were dried over MgSO4, filtered and concentrated to give the desired 7-amino-benzo[b]thiophene-2-carboxylic acid methyl ester (100%).

Workup

  1. customThe excess acid was partially removed in vacuo
  2. additionthe reaction mixture was then poured into a flask (250 mL)
  3. customwas neutralized with saturated NaHCO3 solution at 0° C
  4. additionby adding solid NaHCO3
  5. additionThe resulting aqueous mixture was diluted with EtOAc
  6. customthe Tin-by product was removed
  7. filtrationby filtering through a pad of diatomaceous earth
  8. washThe pad was rinsed with EtOAc
  9. customthe combined filtrates were partitioned in a separatory funnel
  10. extractionThe aqueous layer was extracted with EtOAc two times
  11. dry with materialThe combined organics were dried over MgSO4
  12. filtrationfiltered
  13. concentrationconcentrated

Sources & evidence

ORD record
ord-10b700a9a63b47bf8cda1cd734e844ef
Source dataset
uspto-grants-2009_06
Patent number
US07550461B2

Reaction notes

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