2-(Di-tert-butylphosphino)biphenyl → HCID 58834358, compound

Participants

Reaction Conditions

Reaction Steps

To a vial containing piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (907 mg, 4.04 mmol), was added 4-bromo-1-chloro-2-methoxybenzene (913 mg, 4.12 mmol), palladium acetate (33 mg, 0.14 mmol) and 2-(di-tert-butylphosphino)biphenyl (88 mg, 0.29 mmol). The vial was evacuated and back-filled with nitrogen and to it was added toluene (2 mL). The reaction mixture was heated to 80° C. for 5 min to give a homogeneous solution. Upon cooling to room temperature, sodium tert-butoxide (557 mg, 5.80 mmol) was added to the reaction solution. The resultant mixture was again heated to 80° C. After 4 h, the reaction mixture was cooled to room temperature, then diluted with EtOAc (10 mL) and hexanes (10 mL). The resultant solution was filtered through celite, and the filtrate concentrated in vacuo and purified by silica gel flash chromatography (30 g) (20% EtOAc/Hexanes) to afford 4-(4-chloro-3-methoxyphenyl)piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (63) (239 mg, 15% yield): HPLC retention time=2.72 minutes. MS (ES) [M+H]+ expected 385.2, found 385.1.

Provenance & Evidence