2-Bromo-5-fluorobenzotrifluoride → (R)-1-(4-fluoro-2-(trifluoromethyl)phenyl)-3-methylpiperazine

Participants

Reaction Conditions

Reaction Steps

1-bromo-4-fluoro-2-(trifluoromethyl)benzene (10 g, 41.15 mmol), (R)-2-methylpiperazine (4.33 g, 43.21 mmol), sodium tert-butoxide (7.91 g, 82.31 mmol) and BINAP (1.025 g, 1.65 mmol) in anhydrous toluene (100 mL) was degassed under vacuum with inlet of nitrogen. TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (0.754 g, 0.82 mmol) was added, the mixture again degassed. The resulting suspension was stirred at 100 °C for 4 hours under nitrogen. LCMS: Product formed. Heated for a further 2 hours. LCMS: Reaction complete. Cooled and evaporated. Residue diluted with diethyl ether (75 mL), filtered through Celite and the filtrates extracted with 2M HCl (2x30 mL). The combined aqueous layers were basified with solid NaOH to pH ~10, extracted with diethyl ether (2x50 mL), the organic extracts washed with water (2x10 mL) and brine, dried over MgSO4, filtered and evaporated to give crude product (3.2g, 59%) as an orange oil which was used without further purification.

Provenance & Evidence