Reaktion #70728

Reaktionsgleichung

Trimethylboroxine

EtOAc

methyl 2-bromo-6-chloro-1-isopropyl-3-methyl-1H-indole-4-carboxylate

Trimethylboroxine

potassium carbonate

→

methyl 6-chloro-1-isopropyl-2,3-dimethyl-1H-indole-4-carboxylate

Ausbeute 81.3%

Lösungsmittel

—

hexanes

1,4-Dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction was concentrated under vacuum
2. 2
   Waschenwashed with water
3. 3
   Trocknendried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated under vacuum
6. 6
   SonstigePurification by silica gel chromatography (Analogix

Vorschrift

To a stirred solution of methyl 2-bromo-6-chloro-1-isopropyl-3-methyl-1H-indole-4-carboxylate (0.50 g, 1.451 mmol), Trimethylboroxine (0.30 mL, 2.146 mmol) and potassium carbonate (0.31 g, 2.243 mmol) in 1,4-Dioxane (20 mL) under N2 was added palladium tetrakis (0.18 g, 0.156 mmol). The reaction was heated to 110° C. and stirred for 18 hr. After 3 hr an additional 100 uL Trimethylboroxine was added. The reaction was concentrated under vacuum, taken up in EtOAc, washed with water, dried (MgSO4), filtered and concentrated under vacuum. Purification by silica gel chromatography (Analogix, SF25-60 g, 0 to 10% EtOAc in hexanes) gave the product methyl 6-chloro-1-isopropyl-2,3-dimethyl-1H-indole-4-carboxylate (0.33 g, 1.180 mmol, 81% yield) as a clear thick oil. 1H NMR (400 MHz, DMSO-d6) δ=7.80 (d, J=2.0 Hz, 1H), 7.28 (d, J=1.8 Hz, 1H), 4.81 (dt, J=6.9, 13.9 Hz, 1H), 3.87 (s, 3H), 2.39 (s, 3H), 2.13 (s, 3H), 1.51 (d, J=7.1 Hz, 6H) MS (ES)+m/e 280.1 [M+H]+.

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