Boron trifluoride etherate → 2-Benzyl-6-nitro-1,2,3,4-tetrahydroisoquinoline

HRID 1954426Notes

Reaction equation

HRID 1954426 reaction equation
[BH4-].[Na+].B(F)(F)F.CCOCC.[CH2:12]([N:19]1[C:28](=O)[CH2:27][C:26]2[C:21](=[CH:22][CH:23]=[C:24]([N+:30]([O-:32])=[O:31])[CH:25]=2)[C:20]1=O)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[OH-].[Na+]>C1COCC1>[CH2:12]([N:19]1[CH2:28][CH2:27][C:26]2[C:21](=[CH:22][CH:23]=[C:24]([N+:30]([O-:32])=[O:31])[CH:25]=2)[CH2:20]1)[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 14798Sodium HydroxideHCID 4311764Sodium borohydrideHCID 232961796-Nitro-2-(phenylmethyl)-1,3(2H,4H)-isoquinolinedione

Product 1

HCID 222696172-Benzyl-6-nitro-1,2,3,4-tetrahydroisoquinolineYield 104.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
25 °C

Procedure

To a suspension of sodium borohydride (2.13 g, 56.2 mmole) in THF (56 mL) at 0° C. was added boron trifluoride etherate (9 mL, 73 mmole) dropwise. After stirring the contents for 1 hr., dione (16) (5.0 g, 16.9 mmole) in THF (150 mL) was added at 0° C. over a period of 1.5 hr. The contents were warmed to 25° C. for 30 min. and then refluxed for 16 hr. The completed reaction was cooled to 0° C. and cautiously quenched with aqueous 1N sodium hydroxide (75 mL, 75 mmole) while maintaining the temperature at approximately 9° C. The quenched reaction was stirred for 30 min. at 0° C., 1 hr. at 25° C., 50° C. for 18 hrs. and then cooled to 20° C. The solvents were removed under vacuum, ethyl acetate (100 mL) was added and the layers separated. The organic layer was washed with brine, treated with sodium sulfate and the solvents removed under vacuum to afford 4.73 g of a light brown oil which was of sufficient purity to employ in the next step.

Workup

  1. temperaturerefluxed for 16 hr
  2. customThe completed reaction
  3. temperaturewas cooled to 0° C.
  4. temperaturewhile maintaining the temperature at approximately 9° C
  5. customThe quenched reaction
  6. stirringwas stirred for 30 min. at 0° C., 1 hr
  7. waitat 25° C., 50° C. for 18 hrs
  8. temperatureand then cooled to 20° C
  9. customThe solvents were removed under vacuum, ethyl acetate (100 mL)
  10. additionwas added
  11. customthe layers separated
  12. washThe organic layer was washed with brine
  13. additiontreated with sodium sulfate
  14. customthe solvents removed under vacuum

Sources & evidence

ORD record
ord-a87e9bf2683843f6964dcfba3f2aeed2
Source dataset
uspto-grants-2000_09
Patent number
US06121283

Reaction notes

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