tert-Butyl acrylate → ethyl 1-(2-tert-butoxycarbonylethyl)-4-methyl-1H-indole-2-carboxylate

HRID 355690Notes

Reaction equation

HRID 355690 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[CH:4]=[C:5]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[NH:6]2.[C:16]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])(=[O:19])[CH:17]=[CH2:18].[OH-].C([N+](C)(C)C)C1C=CC=CC=1>O1CCOCC1>[C:21]([O:20][C:16]([CH2:17][CH2:18][N:6]1[C:7]2[C:3](=[C:2]([CH3:1])[CH:10]=[CH:9][CH:8]=2)[CH:4]=[C:5]1[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[O:19])([CH3:24])([CH3:23])[CH3:22]

Participants

5

Reactant 3

HCID 15458tert-Butyl acrylateHCID 66854Benzyltrimethylammonium hydroxideHCID 12529972Ethyl 4-methyl-1H-indole-2-carboxylate

Product 1

HCID 15548944ethyl 1-(2-tert-butoxycarbonylethyl)-4-methyl-1H-indole-2-carboxylateYield 87%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

A mixture of ethyl 4-methyl-1H-indole-2-carboxylate (70.0 g, 344 mmol), tert-butyl acrylate (53.0 g, 413 mmol), benzyltrimethylammonium hydroxide (5.76 g, 34.4 mmol) and 1,4-dioxane (1,000 ml) was stirred at 60°-62° C. for 8.5 hours. The solvent was distilled off under reduced pressure and water (1,000 ml) and acetic acid (30 ml) were added to the residue, followed by extraction with ethyl acetate (twice). The extract solution was washed with a 5% aqueous sodium hydrogencarbonate solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was crystallized from isopropanol (230 ml) to obtain ethyl 1-(2-tert-butoxycarbonylethyl)-4-methyl-1H-indole-2-carboxylate (99.2 g). M.p. 78°-79° C.

Workup

  1. distillationThe solvent was distilled off under reduced pressure and water (1,000 ml) and acetic acid (30 ml)
  2. additionwere added to the residue
  3. extractionfollowed by extraction with ethyl acetate (twice)
  4. washThe extract solution was washed with a 5% aqueous sodium hydrogencarbonate solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationThe solvent was distilled off under reduced pressure
  7. customthe resulting residue was crystallized from isopropanol (230 ml)

Sources & evidence

ORD record
ord-a6f7c0451dee44a0a263b7172008d5dd
Source dataset
uspto-grants-1998_11
Patent number
US05834454

Reaction notes

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