Reaktion #965954

Reaktionsgleichung

ammonium chloride

methyl 4-(cyclopropylcarbonyl)benzoate

lithium hexamethyldisilazane

iodomethane

→

methyl 4-[(1-methylcyclopropyl)carbonyl]benzoate

Ausbeute 8.0%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred overnight
2. 2
   Extraktionthe mixture was extracted with ethyl acetate three times
3. 3
   Waschenwashed with water and saturated brine
4. 4
   Trocknendried over anhydrous sodium sulfate
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→97:3)

Vorschrift

To a solution of methyl 4-(cyclopropylcarbonyl)benzoate (500 mg, 2.45 mmol) in tetrahydrofuran (12 mL) was added dropwise a solution of 1 mol/L lithium hexamethyldisilazane in tetrahydrofuran (3.0 mL, 3.00 mmol) at −78° C. under argon atmosphere, and the mixture was stirred for 15 minutes. To the mixture was added dropwise iodomethane (200 μL, 3.21 mmol) at the same temperature, and the reaction solution was slowly warmed to room temperature and stirred overnight. To the reaction solution was added saturated aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate three times. The organic layer was combined, washed with water and saturated brine, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→97:3) to give methyl 4-[(1-methylcyclopropyl)carbonyl]benzoate (45 mg, 8%) as a colorless oil.

Quelle