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

HRID 1600611Notes

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

Conditions

Temperature: 61 °C

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

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

Sources & evidence

ORD record: ord-6fab74eec8664dc3abf0785da87eaa25
Source dataset: uspto-grants-1999_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05977100

Reaction notes

Loading…