Potassium Carbonate → 3'-(Phenyl)-2,3,5,6-tetrahydro-[1,2']bipyrazinyl-4-carboxylic acid t-butyl ester

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Reaction Steps

Dissolve 3′-chloro-2,3,5,6-tetrahydro-[1,2′]bipyrazinyl-4-carboxylic acid t-butyl ester (2.50 g, 8.40 mmol) and phenylboronic acid (1.23 g, 10.08 mmol) in N,N-dimethylacetamide (25 mL) and water (10 mL). Add tetrakis(triphenylphosphine) palladium(0) (0.49 g, 0.42 mmol) and potassium carbonate (2.80 g, 20.16 mmol). Heat for 4 hr. at 114° C. and allow to cool about 1.5 hr. to room temperature. Partition reaction mixture between MTBE and water. Separate layers. Dry organic layer (sodium sulfate), filter, concentrate and purify (silica gel chromatography eluting with 10:90 to 30:70 ethyl acetate:hexanes), to give 3′-(phenyl)-2,3,5,6-tetrahydro-[1,2′]bipyrazinyl-4-carboxylic acid t-butyl ester (2.49 g, 87%). MS (ES): m/z=341 [M+H]+.

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