Triethylamine → 3'-chloro-4-(5-methyl-1-phenyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazinyl

Participants

Reaction Steps

Dissolve 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl dihydrochloride (0.500 g, 1.84 mmol) in 1,2-dichloroethane (19 mL). Add 5-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (0.396 g, 2.13 mmol), triethylamine (594 μL, 4.26 mmol), sodium triacetoxyborohydride (0.677 g, 3.20 mmol) and acetic acid (200 μL) and stir at room temperature for 18 hr. Add aq. saturated sodium bicarbonate and extract four times with DCM. Dry combined organic layers (magnesium sulfate), filter, concentrate, and purify (silica gel chromatography, eluting with 0:100 to 100:0 ethyl acetate:hexanes) to give 3′-chloro-4-(5-methyl-1-phenyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl (597 mg, 88%) MS (ES): m/z=369[M+H]+.

Provenance & Evidence