5-Methyl-1-phenyl-1H-pyrazole-4-carboxaldehyde → 3'-Chloro-4-(3-methyl-1-phenyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazinyl

Participants

Reaction Steps

Stir together 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl (2.00 g, 10.07 mmol) and 5-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (2.25 g, 12.08 mmol) in dry tetrahydrofuran (10 mL) at room temperature for 10 min., under nitrogen. Add sodium triacetoxyborohydride (3.20 g, 15.10 mmol) and stir reaction for 1 hr. Quench reaction mixture with saturated aq. sodium bicarbonate (30 mL), then extract with DCM (3×20 mL) and pass through an IST Phase Separator Frit®. Concentrate and purify (silica gel chromatography, eluting with 0:100 to 5:95 methanol:DCM). Concentrate and dry in vacuum oven to give the free base as a brown oil (3.585 g, 96.5%). MS (ES): m/z=369 [M+H]+.

Provenance & Evidence