tert-Butanol → Boc-indole

HRID 1821935Notes

Reaction equation

HRID 1821935 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[C:2]1[C:10]([OH:12])=[O:11].C1N=CN(C(N2C=NC=C2)=O)C=1.[C:25](O)([CH3:28])([CH3:27])[CH3:26]>C1COCC1>[C:25]([O:11][C:10]([C:2]1[NH:1][C:9]2[C:4]([CH:3]=1)=[CH:5][CH:6]=[CH:7][CH:8]=2)=[O:12])([CH3:28])([CH3:27])[CH3:26]

Participants

5

Reactant 3

HCID 6386tert-ButanolHCID 682631,1'-CarbonyldiimidazoleHCID 72899Indole-2-carboxylic acid

Product 1

HCID 11458614Boc-indole

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

1.00 g (6.21 mmol) indole-2-carboxylic acid is dissolved in 15 ml absolute THF, mixed with 1.01 g (6.23 mmol) N,N-carbonyldiimidazole and stirred at room temperature for 1 hour. Thereafter, 0.77 g (6.86 mmol) potassium-tert-butylate and 9.12 g (123 mmol) tert-butanol are added. Following heating under reflux for 6 hours, quenching using 5 ml water, filtrating off, rinsing with THF, drying on sodium sulfate and concentration on the rotary evaporator, a brown solid is obtained as the crude product. Preliminary purification by means of column chromatography on silica gel using a short column with petroleum ether/ethyl acetate 95:5 leaves a white solid which is purified on silica gel by means of column chromatography (flow agent: petroleum ether/ethyl acetate 98:2) and yields the product as a white solid.

Workup

  1. temperatureFollowing heating
  2. temperatureunder reflux for 6 hours
  3. customquenching
  4. filtrationfiltrating off
  5. washrinsing with THF
  6. customdrying on sodium sulfate and concentration on the rotary evaporator
  7. customa brown solid is obtained as the crude product
  8. customPreliminary purification by means of column chromatography on silica gel using a short column with petroleum ether/ethyl acetate 95:5
  9. customleaves a white solid which
  10. customis purified on silica gel by means of column chromatography (flow agent: petroleum ether/ethyl acetate 98:2)

Sources & evidence

ORD record
ord-f1234f727665432e8880327999c12f07
Source dataset
uspto-grants-2009_10
Patent number
US07608633B2

Reaction notes

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