Hydrochloric Acid → (S)-2-amino-1-(2-benzyl-4-(3-(cyclopentyloxy)-4-methoxyphenyl)piperazin-1-yl)ethanone, hydrochloride salt

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Reaction Steps

A solution of (S)-3-Benzyl-1-(3-cyclopentyloxy-4-methoxy-phenyl)-piperazine (Example 2) (73 mg, 0.2 mmol) and BOC-glycine (35 mg, 0.2 mmol) in DMF (1.0 mL) at room temperature was treated with diisopropylethylamine (35 μL, 0.2 mmol) followed by HATU (84 mg, 0.22 mmol). The reaction mixture was stirred for 2 h then partitioned between EtOAc (10 mL) and a saturated aqueous NaHCO3 solution (10 mL). The organic component was isolated and further washed with brine (10 mL) then dried over MgSO4, filtered, and evaporated to an oil which was purified by silica gel flash chromatography with 40% EtOAc/hexane as eluant to afford BOC-containing coupled product as a foam (85 mg, 81%). LC/MS 7.46 min, [M+1]+ 524. The BOC-protected intermediate was dissolved in a 4 N solution of hydrogen chloride in dioxane, and stirred for 2 h then evaporated to a solid which was filtered and washed with diethyl ether to afford product as a colorless solid (42 mg, 49% based on trihydrochloride salt). LC/MS 4.66 min, [M+1]+ 424.

Provenance & Evidence