反応 #60464

反応方程式

Trimethylboroxine

4-[4-bromo-2-(3,3,5,5-tetramethylcyclohexyl)phenyl]piperazine-1-carboxylic acid t-butyl ester

cesium carbonate

dimethylformamide

→

title compound

収率 71.7%

4-[4-Methyl-2-(3,3,5,5-tetramethylcyclohexyl)phenyl]piperazine-1-carboxylic acid t-butyl ester

収率 71.7%

溶媒

ethyl acetate

water

Ethyl acetate

反応条件

後処理

1. 1
   workup.STIRRINGstirring
2. 2
   洗浄The separated organic layer was washed with water and brine in that order
3. 3
   乾燥dried over anhydrous magnesium sulfate
4. 4
   ろ過The desiccant was filtered off
5. 5
   濃縮the filtrate was concentrated under reduced pressure
6. 6
   その他The resultant residue was purified by silica gel column chromatography (ethyl acetate/hexane)

実験手順

A mixture of 4-[4-bromo-2-(3,3,5,5-tetramethylcyclohexyl)phenyl]piperazine-1-carboxylic acid t-butyl ester (200 mg, 0.417 mmol) produced in Example (99a), cesium carbonate (408 mg, 1.25 mmol), tetrakis(triphenylphosphine)palladium(0) (50 mg, 0.0417 mmol) and dimethylformamide (4 mL) was stirred at room temperature under a nitrogen atmosphere. Trimethylboroxine (0.06 mL, 0.417 mmol) was added to the mixture, and stirring was continued for 9 hours at an external temperature of 100° C. Ethyl acetate and water were added to the reaction mixture and extraction was performed with ethyl acetate. The separated organic layer was washed with water and brine in that order and then dried over anhydrous magnesium sulfate. The desiccant was filtered off and the filtrate was concentrated under reduced pressure. The resultant residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give 124 mg of the title compound as colorless crystals.

出典