Acetic Acid → 4-Bromo-5,6,7,8-tetrahydroisoquinolin-8-OL

HRID 714042Notes

Reaction equation

HRID 714042 reaction equation
[Br:1][C:2]1[C:11]2[CH2:10][CH2:9][CH2:8][C:7](=[O:12])[C:6]=2[CH:5]=[N:4][CH:3]=1.[BH4-].[Na+].CC(O)=O>CO>[Br:1][C:2]1[C:11]2[CH2:10][CH2:9][CH2:8][CH:7]([OH:12])[C:6]=2[CH:5]=[N:4][CH:3]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 4311764Sodium borohydrideHCID 717433804-Bromo-6,7-dihydro-8(5H)-isoquinolinone

Product 1

HCID 717438914-Bromo-5,6,7,8-tetrahydroisoquinolin-8-OLYield 92%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

A suspension of 4-bromo-6,7-dihydroisoquinolin-8(5H)-one (intermediate A-1[C]) (2.135 g, 9.44 mmol) in MeOH (18.9 mL) was cooled to 0° C. and treated with NaBH4 (357 mg, 9.44 mmol) in 5 portions over 30 min. The reaction was stirred for ¾ h at 0° C., then AcOH was added dropwise until pH ˜5-6 and the reaction mixture was evaporated. The residue was diluted with water and poured on aq. sat. NaHCO3-solution followed by extraction with EtOAc (3×). The organic layers are washed once with aq. sat. NaHCO3 and aq. 10% NaCl solution, dried over Na2SO4 and concentrated in vacuo. The residue was precipitated with CH2Cl2/n-pentane to afford the title compound (1.98 g, 92%) as dark brown viscous oil. MS: 227 (M+, 1 Br).

Workup

  1. customthe reaction mixture was evaporated
  2. additionThe residue was diluted with water
  3. additionpoured on aq. sat. NaHCO3-solution
  4. extractionfollowed by extraction with EtOAc (3×)
  5. washThe organic layers are washed once with aq. sat. NaHCO3 and aq. 10% NaCl solution
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated in vacuo
  8. customThe residue was precipitated with CH2Cl2/n-pentane

Sources & evidence

ORD record
ord-25ea43593bc0466ea81b064e996bb684
Source dataset
uspto-grants-2015_11
Patent number
US09187429B2

Reaction notes

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