1H-Indole-5-Carboxylic Acid → Tert-butyl 1H-indole-5-carboxylate

HRID 1821945Notes

Reaction equation

HRID 1821945 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][C:6]([C:10]([OH:12])=[O:11])=[CH:7][CH:8]=2)[CH:3]=[CH:2]1>C1C=CC=CC=1.C(OCC)C>[C:4]([O:11][C:10]([C:6]1[CH:5]=[C:4]2[C:9](=[CH:8][CH:7]=1)[NH:1][CH:2]=[CH:3]2)=[O:12])([CH3:9])([CH3:5])[CH3:3]

Participants

4

Reactant 1

HCID 742801H-Indole-5-Carboxylic Acid

Product 1

HCID 11183550Tert-butyl 1H-indole-5-carboxylate

Reagents, catalysts & solvents 2

HCID 241BenzeneSolvent2×HCID 3283Diethyl EtherSolvent

Procedure

0.50 g (3.10 mmol) indole-5-carboxylic acid is suspended in 20 ml absolute benzene and heated under reflux. A solution of 2.80 g (12.39 mmol) 90% N,N-dimethylformamidedi-tert-butylacetal in 20 ml absolute benzene is added drop-wise within 30 min. Following another heating under reflux for 30 minutes and subsequent cooling, the reaction mixture is diluted with diethyl ether, washed with 5% sodium carbonate solution and with saturated NaCl solution. Drying on sodium sulfate, filtration and concentration on the rotary evaporator leave as a crude product a yellow oil which is purified on silica gel by means of column chromatography (flow agent: petroleum ether/ethyl acetate 95:5) and yields the product as a white solid.

Workup

  1. temperatureheated
  2. temperatureunder reflux
  3. temperatureunder reflux for 30 minutes
  4. washwashed with 5% sodium carbonate solution and with saturated NaCl solution
  5. customDrying on sodium sulfate, filtration and concentration on the rotary evaporator
  6. customleave as a crude product a yellow oil which
  7. customis purified on silica gel by means of column chromatography (flow agent: petroleum ether/ethyl acetate 95:5)

Sources & evidence

ORD record
ord-2c05a6bf02d6418890bfbd2d26790750
Source dataset
uspto-grants-2009_10
Patent number
US07608633B2

Reaction notes

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