A mixture of 3-Bromo-2-methyl-6-(1-(tetrahydro-2H-pyran-2-yl)-1H-1,2,4-triazol-3-yl)pyridine (1 equiv), bis(pinacolato)diboron (1.05 equiv), potassium acetate (2 equiv), potassium carbonate (3 equiv), [1,1′-bis(diphenylphosphino)-ferrocene]dichloropalladium(II), complex with dichloromethane (1:1) (0.1 equiv) in anhydrous dioxane was degassed and heated at 90° C. for 2 h. The mixture was cooled to <40° C. and 7-bromo-1-ethyl-3,4-dihydropyrazino[2,3-b]pyrazin-2(1H)-one (1 equiv), water and [1,1′-bis(diphenylphosphino)-ferrocene]dichloropalladium(II), complex with dichloromethane (1:1) (0.05 equiv) were added. The mixture was degassed and heated at 65-70° C. under nitrogen for 1 h. The mixture was cooled to <40° C., diluted with water and ethyl acetate. Standard ethyl acetate/water work up followed by flash column chromatography (0-5% methanol in dichloromethane) gave the title compound in 57% yield. 1H NMR (400 MHz, DMSO-d6) δ (ppm) 7.99 (s, 2H), 7.93 (s, 1H), 7.72 (s, 1H), 4.22 (s, 2H), 4.05 (q, J=6.77 Hz, 2H), 2.71 (s, 3H), 1.18 (t, J=7.03 Hz, 3H); MS (ESI) m/z 337.6 [M+1]+.
