反应详情

温度

100 °C

3-Methyl-piperazine-1,3-dicarboxylic acid 1-tert-butyl ester (120 mg, 0.49 mmol) and 2-Bromo-5-trifluoromethyl-pyridine (133 mg, 0.59 mmol) were dissolved in 2.0 mL of anhydrous toluene (degassed). In a separate, septum-equipped vial were placed tri(dibenzylideneacetone)dipalladium (0) (22 mg, 0.024 mmol), 1,3-bis(2,6-di-1-propylphenyl)imidazolium chloride (42 mg, 0.1 mmol) and sodium t-butoxide (57 mg, 0.59 mmol). This “catalytic” vial was equipped with a magnetic stir bar and flushed with dry nitrogen. The reactant solution was next transferred to the “catalytic” vial and the mixture was stirred at 100° C. for 5 h. After this period the mixture was combined with 20 mL of hexane/EtOAc (2:1) and was passed through a pad of Celite. The resulting filtrate was evaporated in vacuo and purified using flash silica chromatography (0-20% EtOAc/Hexane) to yield 110 mg (58%) of 4-(5-Trifluoromethyl-pyridin-2-yl)-piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester.

1. customIn a separate, septum-equipped vial
2. customThis “catalytic” vial was equipped with a magnetic stir bar
3. customflushed with dry nitrogen
4. waitAfter this period the mixture was combined with 20 mL of hexane/EtOAc (2:1)
5. customThe resulting filtrate was evaporated in vacuo
6. custompurified