Ammonium Chloride → Methyl 7-amino-2,3-dihydro-1,4-benzodioxin-6-carboxylate

HRID 1595774Notes

Reaction equation

HRID 1595774 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:14]([N+:15]([O-])=O)=[CH:13][C:8]2[O:9][CH2:10][CH2:11][O:12][C:7]=2[CH:6]=1)=[O:4].[NH4+].[Cl-]>CO.O.[Fe]>[CH3:1][O:2][C:3]([C:5]1[C:14]([NH2:15])=[CH:13][C:8]2[O:9][CH2:10][CH2:11][O:12][C:7]=2[CH:6]=1)=[O:4]

Participants

6

Reactant 2

HCID 25517Ammonium Chloride3×HCID 10537941Methyl 7-Nitro-1,4-benzodioxane-6-carboxylate

Product 1

HCID 3146109Methyl 7-amino-2,3-dihydro-1,4-benzodioxin-6-carboxylateYield 90.5%

Reagents, catalysts & solvents 3

HCID 23925IronCatalyst3×HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

A mixture of 12.0 g (50.2 mmol) of 7-nitro-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid methyl ester, 11.2 g (201 mmol) of powdered Fe and 13.3 g (257 mmol) of NH4Cl in 175 ml of MeOH and 70 mL of H2O was refluxed for 5.5 h. An additional 11.2 g of Fe and 13.3 g of NH4Cl was added and the mixture was heated for 5.5 h more. Finally, 5.5 g of Fe and 6.5 g of NH4Cl was added and the mixture was heated for 4 h. The cooled reaction was filtered through Celite, the pad was washed well with MeOH and the filtrate and washings were combined. The solvent was removed and the residue was slurried in H2O and collected. The crude product was filtered through silica (CHCl3) to give 9.5 g of the title compound as tan crystals: mass spectrum (electrospray, m/e): M+H 209.9.

Workup

  1. temperaturewas refluxed for 5.5 h
  2. temperaturethe mixture was heated for 5.5 h more
  3. temperaturethe mixture was heated for 4 h
  4. customThe cooled reaction
  5. filtrationwas filtered through Celite
  6. washthe pad was washed well with MeOH
  7. customThe solvent was removed
  8. customcollected
  9. filtrationThe crude product was filtered through silica (CHCl3)

Sources & evidence

ORD record
ord-39f8ae95eb1a4941a9cbe6b8d592ceb0
Source dataset
uspto-grants-2001_09
Patent number
US06288082B1

Reaction notes

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