Potassium borohydride → 8-Amino-5-bromo-1,2,3,4-tetrahydronaphthalen-1-ol

HRID 2114544Notes

Reaction equation

HRID 2114544 reaction equation
[BH4-].[K+].[Br:3][C:4]1[CH:13]=[CH:12][C:11]([N+:14]([O-])=O)=[C:10]2[C:5]=1[CH2:6][CH2:7][CH2:8][C:9]2=[O:17]>CO>[NH2:14][C:11]1[CH:12]=[CH:13][C:4]([Br:3])=[C:5]2[C:10]=1[CH:9]([OH:17])[CH2:8][CH2:7][CH2:6]2

Participants

4

Reactant 2

HCID 4192641Potassium borohydrideHCID 199907905-bromo-3,4-dihydro-8-nitro-2H-naphthalen-1-one

Product 1

HCID 692133418-Amino-5-bromo-1,2,3,4-tetrahydronaphthalen-1-olYield 70%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To prepare this compound, potassium borohydride (0.28 g, 5.2 mmol) was added in portions to a suspension of 5-bromo-3,4-dihydro-8-nitro-2H-naphthalen-1-one (0.20 g, 0.74 mmol) and Cu2Cl2 (0.22 g, 2.2 mmol) in 2 mL anhydrous methanol at room temperature. After 20 minutes, the methanol was evaporated under reduced pressure. The residue was extracted with a mixture of EtOAc and water. The EtOAc layer was washed sequentially with water and brine, dried over sodium sulfate, filtered, and concentrated. Flash chromatography (18% EtOAc/hexanes) afforded 0.12 g (70%) of 8-amino-5-bromo-1,2,3,4-tetrahydronaphthalen-1-ol, a light brown solid. 1H NMR (500 MHz, CDCl3) δ 7.27 (d, J=8.5, 1H), 6.47 (d, J=8.5, 1H), 4.77 (dd, J=4.0, 3.4, 1H), 2.9-4.0 (very broad, 3H), 2.82-2.90 (m, 1H), 2.46-2.56 (m, 1H), 2.00-2.08 (m, 1H), 1.7-1.9 (m, 3H).

Workup

  1. customthe methanol was evaporated under reduced pressure
  2. extractionThe residue was extracted with a mixture of EtOAc and water
  3. washThe EtOAc layer was washed sequentially with water and brine
  4. dry with materialdried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-4823dfbe44334be49a1394dd1816453b
Source dataset
uspto-grants-2008_10
Patent number
US07435733B2

Reaction notes

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