Potassium Carbonate → HCID 67367110, compound

Participants

Reaction Steps

Charge a reactor with 2,3-dichloropyrazine (73.6 g, 0.497 mol, 1.0 equiv), piperazine-1-carboxylic acid t-butyl ester (101.9 g, 0.547 mol, 1.1 equiv) and powdered potassium carbonate (164.8 g, 1.19 mol, 2.4 equiv). Add N,N-dimethylacetamide (1.1 L) and heat to 110° C. under nitrogen for 5 hr. Cool the reaction to room temperature, and add 4-fluorophenylboronic acid (83.4 g, 0.596 mol, 1.2 equiv), tetrakis(triphenyl-phosphine)palladium(0) (2.87 g, 2.5 mmol, 0.005 equiv) and water (442 mL). Heat the reaction to 110° C. under a nitrogen atmosphere for 5 hr. Cool the reaction to 60° C. and dilute with water (800 mL) and methyl t-butyl ether (1.0 L). Cool to room temperature and separate the resulting layers. Wash the organic layer with 200 mL of water, separate the layers, and concentrate to give 3-(4-fluorophenyl)-2-[4-(t-butyloxycarbonyl)piperazin-1-yl]pyrazine as a light yellow solid that is taken into the next step without further purification.

Provenance & Evidence