Reaction #84207

Reaction equation

1-bromopentane

Indole 3-carboxylic acid

sodium hydride

→

title compound

Yield 49.0%

3-carboxy-1-pentyl-1H-indole

Yield 49.0%

Solvents

DMF

DMF

Conditions

Workup

1. 1
   workup.STIRRINGThe mixture was stirred at room temperature overnight
2. 2
   OtherThe solvents were removed in vacuo and to the residue
3. 3
   workup.ADDITIONwas added water (30 ml) and ethyl acetate (30 ml)
4. 4
   OtherThe ethyl acetate portion was separated
5. 5
   Dryingdried over sodium sulphate
6. 6
   Filtrationfiltered
7. 7
   Otherevaporated to dryness
8. 8
   OtherThe crude residue was purified by column chromatography (silica gel: 20% ethyl acetate in hexane)

Procedure

Indole 3-carboxylic acid (3 g, 18.62 mmol) was added to a suspension of sodium hydride (60% in oil) (1.11 g, 1.5 eq) in dry DMF (30 ml) under a nitrogen atmosphere. The mixture was stirred at room temperature for 45 min (H2 evolving has ceased) and to this was added 1-bromopentane (4.62 ml, 2 eq) in dry DMF (10 ml) dropwise. The mixture was stirred at room temperature overnight. The solvents were removed in vacuo and to the residue was added water (30 ml) and ethyl acetate (30 ml). The ethyl acetate portion was separated, dried over sodium sulphate, filtered and evaporated to dryness. The crude residue was purified by column chromatography (silica gel: 20% ethyl acetate in hexane) to give the title compound (2.12 g, 49%) as a cream solid.

Source