3,4-Dimethoxyaniline → 2-Bromo-4,5-dimethoxyaniline

HRID 1191326Notes

Reaction equation

HRID 1191326 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([NH2:11])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].C1C(=O)N([Br:19])C(=O)C1>C1COCC1.OS(O)(=O)=O>[Br:19][C:6]1[CH:7]=[C:8]([O:9][CH3:10])[C:3]([O:2][CH3:1])=[CH:4][C:5]=1[NH2:11]

Participants

5

Reactant 2

HCID 227703,4-DimethoxyanilineHCID 67184N-bromobutanimide

Product 1

HCID 4140762-Bromo-4,5-dimethoxyaniline

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3,4-dimethoxybenzenamine (20.0 g, 0.130 mol) in dry THF (200 mL) was added concentrated H2SO4 (20 drops) under N2 at −78° C. After 10 mains, NBS (23.2 g, 0.130 mol) was added in potions at −78° C. Then the reaction mixture was allowed to gradually warm up to room temperature over 1 hour. THF was removed under reduced pressure. The residue was diluted with EtOAc (200 mL), and washed with water (80 mL×3). The organic layer was dried over anhydrous MgSO4, filtered and concentrated in vacuum. The residue was purified by silica gel column (15:1 hexanes/ethyl acetate) to afford 2-bromo-4,5-dimethoxyaniline as a yellow solid. MS (M+H)=232 and 234.

Workup

  1. customTHF was removed under reduced pressure
  2. additionThe residue was diluted with EtOAc (200 mL)
  3. washwashed with water (80 mL×3)
  4. dry with materialThe organic layer was dried over anhydrous MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuum
  7. customThe residue was purified by silica gel column (15:1 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-d7f47caaeadf4bc581c2997dd85ae8ec
Source dataset
uspto-grants-2014_03
Patent number
US08680116B2

Reaction notes

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