Indole → 1-Benzylindole

HRID 1636194Notes

Reaction equation

HRID 1636194 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.[OH-].[K+].C1OCCOCCOCCOCCOCCOC1.[CH2:30](Cl)[C:31]1[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=1>C1C=CC=CC=1.C(OCC)C>[CH2:30]([N:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1)[C:31]1[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=1

Participants

7

Reactant 4

HCID 798IndoleHCID 7503Benzyl ChlorideHCID 14797Potassium HydroxideHCID 2855718-Crown-6

Product 1

HCID 969131-BenzylindoleYield 25%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolvent2×HCID 3283Diethyl EtherSolvent

Procedure

A mixture of indole (1) (0.03 mole, 3.51 g), potassium hydroxide (0.03 mole, 1.97 g)) powdered in a mortar and 18-crown-6 ether (0.001 mole, 250 mg) in benzene (20 cm3) is heated under reflux with vigorous stirring for two hours. A solution of benzyl chloride (26) (0.04 mole, 5.06 g) in benzene (10 cm3) is added to the above mixture and reflux is maintained for an additional four hours. The reaction is monitored by TLC. The reaction mixture is filtered on Celite. Evaporation of the solvent gives an orange liquid which is purified by dry column chromatography eluted using a mixture of dichloromethane in 50% petroleum ether. Evaporation of the solvent gives a colourless thick liquid which is solidified in the presence of diethyl ether to give a white solid of 1-benzylindole (3b) (1.2 g, 0.007 mole, 25%), m.p. 48-51° C., shown to be pure by 1H nmr.

Workup

  1. temperatureis heated
  2. temperatureunder reflux
  3. temperaturereflux
  4. temperatureis maintained for an additional four hours
  5. filtrationThe reaction mixture is filtered on Celite
  6. customEvaporation of the solvent
  7. customgives an orange liquid which
  8. customis purified
  9. customby dry column chromatography
  10. washeluted
  11. additiona mixture of dichloromethane in 50% petroleum ether
  12. customEvaporation of the solvent
  13. customgives a colourless thick liquid which

Sources & evidence

ORD record
ord-6763100d866a4d46b847031abb52557b
Source dataset
uspto-grants-2000_03
Patent number
US06033601

Reaction notes

Loading…