Sodium borohydride → 1-benzyl-4-methyl-2,3,9,9a-tetrahydro-1H-indeno[2,1-b]pyridine

HRID 521020Notes

Reaction equation

HRID 521020 reaction equation
[BH4-].[Na+].[Br-].[CH2:4]([N+:11]1[CH:16]=[CH:15][C:14]([CH3:17])=[C:13]2[C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][C:23]=3[CH2:24][C:12]=12)[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1>C(O)C>[CH2:4]([N:11]1[CH2:16][CH2:15][C:14]([CH3:17])=[C:13]2[C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][C:23]=3[CH2:24][CH:12]12)[C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 671942071-benzyl-4-methyl-9H-indeno[2,1-b]pyridinium bromide

Product 1

HCID 582946471-benzyl-4-methyl-2,3,9,9a-tetrahydro-1H-indeno[2,1-b]pyridine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
60 °C

Procedure

Sodium borohydride (0.15 g) is added to a suspension of 1-benzyl-4-methyl-9H-indeno[2,1-b]pyridinium bromide (0.92 g) in ethanol (10 mL) chilled in an ice bath. The cooling bath is removed and the mixture is stirred at room temperature for 1 h and at 60° C. for 2 h. More sodium borohydride (0.18 g) is added and stirring is continued at reflux temperature for 4 h. After the addition of another portion of sodium borohydride (0.10 g), the mixture is stirred at reflux temperature overnight. After cooling to room temperature, ice-cold water is added and the precipitate is separated by filtration. The precipitate is dissolved in ether, the resulting solution is dried (Na2SO4), and the solvent is evaporated to afford the crude product that is used without further purification. Yield: 0.66 g (crude); Mass spectrum (ESI+): m/z=276 [M+H]+.

Workup

  1. temperaturechilled in an ice bath
  2. customThe cooling bath is removed
  3. additionMore sodium borohydride (0.18 g) is added
  4. stirringstirring
  5. temperatureat reflux temperature for 4 h
  6. additionAfter the addition of another portion of sodium borohydride (0.10 g)
  7. stirringthe mixture is stirred
  8. temperatureat reflux temperature overnight
  9. temperatureAfter cooling to room temperature
  10. additionice-cold water is added
  11. customthe precipitate is separated by filtration
  12. dissolutionThe precipitate is dissolved in ether
  13. dry with materialthe resulting solution is dried (Na2SO4)
  14. customthe solvent is evaporated

Sources & evidence

ORD record
ord-463e24c131a4446d9a8497e834c88055
Source dataset
uspto-grants-2016_05
Patent number
US09328072B2

Reaction notes

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