Potassium Carbonate → Tert-butyl 5-(pyrazin-2-yl)picolinate

Participants

Reaction Conditions

Reaction Steps

The 250 mL flask was charged with tert-butyl 5-bromopicolinate 34h-4 (12.9 g, 50 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (13.9 g, 55 mmol), KOAc (9.8 g, 100 mmol), PdCl2(dppf)-CH2Cl2 adduct (0.408 g, 0.5 mmol) and THF (80 mL). The flask was sealed under nitrogen and the mixture was stirred at 80° C. for 24 hours. After completion of the reaction, it was cooled to room temperature and filtered through Celite. The filtrate was taken in 500 mL 4-necked RB flask and charged with aqueous K2CO3 solution (13.8 g in 100 ml Of water), 2-chloropyrazine (6.8 g, 60 mmol), and PdCl2(dppf)-CH2Cl2 adduct (0.204 g, 0.25 mmol). The reaction mixture was stirred at 64° C. for 2 h under nitrogen, cooled to room temperature and filtered through Celite. The filtrate was diluted with i-PrOAc (100 mL) and the aqueous layer separated. The organic layer was washed with water (2×100 mL), concentrated to ˜20 mL of volume and diluted with heptane (200 mL). The solid was collected by filtration, washed with heptane (50 mL), and dried at 40° C. to obtain 34h-1 as a pale yellow solid.

Provenance & Evidence