1,2-Dichloroethane → 2-{4-[3'-(2-Fluoro-phenyl)-2,3,5,6-tetrahydro-[1,2']bipyrazinyl-4-ylmethyl]-pyrazol-1-yl}-ethanol hydrochloride

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Reaction Steps

Dissolve 3′-(2-fluoro-phenyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl (0.213 g, 0.825 mmol) in DCE (5 mL). Add 1-(2-hydroxy-ethyl)-1H-pyrazole-4-carbaldehyde (0.137 g, 0.990 mmol) followed by sodium triacetoxyborohydride (0.262 g, 1.24 mmol) and stir at ambient temperature for 18 hr. Add additional 1-(2-hydroxy-ethyl)-1H-pyrazole-4-carbaldehyde (0.093 g, 0.663 mmol) and stir at ambient temperature for 18 hr. Purify via SCX chromatography followed by silica gel chromatography, (eluting with 100:0 to 0:100 hexanes:ethyl acetate, then 10:90 methanol:ethyl acetate), to give the free base of the title compound (116 mg, 37%). Dissolve the free base (0.114 g, 0.298 mmol) in methanol and add a solution of ammonium chloride (0.016 g, 0.298 mmol) in a minimal volume of methanol. Shake for 18 hr. at ambient temperature and concentrate to give the title compound (125 mg, 100%). MS (ES): m/z=383[M+H]+.

Provenance & Evidence