1,2-Dibromoethane → 1h-Indole-1-carboxylic acid,7-bromo-2,3-dihydro-5-methoxy-,1,1-dimethylethyl ester
Reaction equation
[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([O:17][CH3:18])=[CH:14][CH:15]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].CN(CCN(C)C)C.[Li]C(CC)C.[Br:32]CCBr>CCOCC>[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([O:17][CH3:18])=[CH:14][C:15]=2[Br:32])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]Participants
6
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -40 °C
Procedure
To 1-(tert-Butoxycarbonyl)-5-methoxyindoline (2.0 g) and TMEDA (1.57 mL, 1.3 eq.) in ether (40 mL) at −78° C. was added sec-BuLi (7.4 mL, 1.2 eq.). The reaction was warmed to −40° C. for 2 hours and then cooled to −78° C. 1,2-dibromoethane (2.07 mL, 3 eq.) was added and the reaction stirred for 45 minutes at −78° C. The bath was then removed and the reaction was stirred for 1 hour. The reaction was quenched with water and extracted with ether. The ether was washed with brine, dried over MgSO4, and concentrated. The crude product was chromatographed on silica gel, using hexane/ethyl acetate (19:1) as eluent, affording 1-(tert-butoxycarbonyl)-7-bromo-5-methoxyindoline (1.16 g).
Workup
- temperaturecooled to −78° C
- customThe bath was then removed
- stirringthe reaction was stirred for 1 hour
- customThe reaction was quenched with water
- extractionextracted with ether
- washThe ether was washed with brine
- dry with materialdried over MgSO4
- concentrationconcentrated
- customThe crude product was chromatographed on silica gel
Sources & evidence
- ORD record
- ord-4cbc253908044c1b964dc398948dca8b
- Source dataset
- uspto-grants-2001_06
- Patent number
- US06245769B1
Reaction notes
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