Water → 1-Benzyl-4-isopropyl-3,6-dihydro-2H-pyridine

HRID 1518955Notes

Reaction equation

HRID 1518955 reaction equation
[BH4-].[Na+].[Br-].[CH2:4]([N+:11]1[CH:16]=[CH:15][C:14]([CH:17]([CH3:19])[CH3:18])=[CH:13][CH:12]=1)[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.O>CCO>[CH2:4]([N:11]1[CH2:12][CH:13]=[C:14]([CH:17]([CH3:19])[CH3:18])[CH2:15][CH2:16]1)[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

5

Reactant 3

HCID 962WaterHCID 4311764Sodium borohydrideHCID 89713591HCID 89713591, compound

Product 1

HCID 597479711-Benzyl-4-isopropyl-3,6-dihydro-2H-pyridineYield 85.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Add sodium tetrahydroborate (1.8 g, 47.4 mmol) in portions to a solution of 1-benzyl-4-isopropyl-pyridin-1-ium bromide (11.1 g, 36.5 mmol) in EtOH (55 mL) at 0° C. Allow the reaction mixture to reach ambient temperature slowly and stir overnight. Add 10 mL of water and remove the organic solvent under vacuum. Add water and then adjust the pH with HCl (5M) to a pH of 1-2. Stir the mixture for 15 min and then add NaOH (2M) until the pH is 8-9. Extract the aqueous layer with EtOAc, combine the organic layers; and sequentially wash with NaOH (2M) then brine. Dry the organic over anhydrous sodium sulphate; filter; and concentrate the filtrate. Purify the compound by chromatography on a silica gel cartridge eluting with hexane:ethyl acetate (9:1, 7:3, 5:5, and then 100% ethyl acetate) to obtain the title compound as a pale yellow oil (6.7 g, 83%). MS (m/z): 216 (M+1).

Workup

  1. customto reach ambient temperature
  2. customremove the organic solvent under vacuum
  3. stirringStir the mixture for 15 min
  4. extractionExtract the aqueous layer with EtOAc
  5. washand sequentially wash with NaOH (2M)
  6. dry with materialDry the organic over anhydrous sodium sulphate
  7. filtrationfilter
  8. concentrationand concentrate the filtrate
  9. customPurify the compound by chromatography on a silica gel cartridge
  10. washeluting with hexane:ethyl acetate (9:1, 7:3, 5:5

Sources & evidence

ORD record
ord-610f3f39bbec4ff8ad32cb3951b91b20
Source dataset
uspto-grants-2015_07
Patent number
US09073856B2

Reaction notes

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