Methylamine → Methyl-carbamic acid 4-[4-(1,5-dimethyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazinyl-3'-yl]-benzyl ester hydrochloride

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Reaction Steps

Dissolve {4-[4-(1,5-dimethyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl-3′-yl]-phenyl}-methanol (200 mg, 0.53 mmol) in DCM (5 mL) at room temperature under nitrogen. Add carbonyl diimidazole (94 mg, 0.58 mmol) and stir for 20 hr. Add a solution of methylamine in tetrahydrofuran (2 M, 2 mL, 4.0 mmol) and stir reaction for 2 hr. at room temperature. Quench reaction with water (10 mL) then extract with DCM (2×10 mL), pass through an IST Phase Separator Frit® and concentrate. Purify by low pH reverse phase HPLC, and form the free base by passing through an SCX-2® ion exchange cartridge washing with methanol then eluting with 3 M ammonia in methanol. Dissolve the oil in acetonitrile and convert to the hydrochloride salt by adding 2 M aq HCl solution. Add water and lyophilize to give the title compound as a yellow powder (28 mg, 12%). MS (ES): m/z=436 [M+H]+

Provenance & Evidence