Triethylamine → (S)-1-(2-benzyl-4-(3-(cyclopentyloxy)-4-methoxyphenyl)piperazin-1-yl)-2-hydroxyethanone

Participants

Reaction Steps

A solution of (S)-3-Benzyl-1-(3-cyclopentyloxy-4-methoxy-phenyl)-piperazine (Example 2) (73 mg, 0.2 mmol) in THF (1.5 mL) at room temperature was treated with triethylamine (42 μL, 0.3 mmol) followed by benzyloxyacetyl chloride (19 μL, 0.2 mmol). The reaction mixture was stirred for 2 h then diluted with EtOAc (2 mL) and water (2 mL). The organic phase was isolated and further washed with an additional portion of a water (2 mL) followed by a brine solution (2 mL). The organic component was dried over MgSO4, filtered, and evaporated to an oil which was purified by silica gel flash chromatography with 20% then 40% EtOAc/hexane as eluant to afford coupled product as an oil (69 mg, 67%). LC/MS 7.64 min, [M+1]+ 515. The intermediate benzyloxy ether (60 mg,0.117 mmol) was dissolved in MeOH (20 mL), purged with a stream of nitrogen, treated with 20% Pd/C (140 mg, 50% water content), and hydrogenated under 40 psi pressure of hydrogen for 4 h. The crude reaction mixture was then purged with nitrogen, filtered, evaporated, and purified by silica gel flash chromatography with 40% then 75% EtOAc/hexane as eluant to afford product as an oil (9 mg, 18%). LC/MS 6.55 min, [M+1]+ 425.

Provenance & Evidence