Reacción #60464

Ecuación de reacción

Trimethylboroxine

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

cesium carbonate

dimethylformamide

→

title compound

Rendimiento 71.7%

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

Rendimiento 71.7%

Disolventes

ethyl acetate

water

Ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirring
2. 2
   LavadoThe separated organic layer was washed with water and brine in that order
3. 3
   Secadodried over anhydrous magnesium sulfate
4. 4
   FiltraciónThe desiccant was filtered off
5. 5
   Concentraciónthe filtrate was concentrated under reduced pressure
6. 6
   OtroThe resultant residue was purified by silica gel column chromatography (ethyl acetate/hexane)

Procedimiento

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.

Fuente