4-Bromo-1,2-dichlorobenzene → HCID 18327742, compound

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a mixture of 4-bromo-1,2-dichlorobenzene (1.81 g, 8.03 mmol), N-methyl-N-(tert-butoxycarbonyl)-4-penten-2-amine (1.60 g, 8.03 mmol), prepared as previously described, palladium(II) acetate (18.0 mg, 0.08 mmol), tri-o-tolylphosphine (97.7 mg, 0.32 mmol), triethylamine (2.5 mL, 17.94 mmol) and anhydrous acetonitrile (5 mL) was stirred and heated under reflux at 80-90° C. (oil bath temperature) for 18 h. TLC analysis on silica gel eluting with EtOAc-hexane (3:1, v/v) indicated an incomplete reaction. Therefore, additional palladium(II) acetate (18.0 mg), tri-o-tolylphosphine (92 mg), triethylamine (2.5 mL) and anhydrous acetonitrile (5 mL) were added and heating was continued at 60° C. for an additional 40 h. The resulting mixture, an oily brown semi-solid, was cooled to ambient temperature, diluted with water (25 mL), and extracted with CH2Cl2 (3×25 mL). The combined CH2Cl2 extracts were dried (Na2SO4), filtered, concentrated by rotary evaporation, and the residue was dried under high vacuum to produce a dark-brown oil (2.81 g). The crude product was purified by column chromatography on silica gel (132 g), eluting with ethyl acetate-hexane (15:85, v/v). Selected fractions containing the product (Rf 0.34) were combined, concentrated by rotary evaporation and the residue was vacuum dried to give 1.38 g (50.0%) of a light-yellow oil.

Provenance & Evidence