Potassium Carbonate → Tert-butyl 6-(1-methyl-1,2,3,4-tetrahydroquinoxalin-6-yl)picolinate

Participants

Reaction Conditions

Reaction Steps

Tert-butyl 6-bromopicolinate (25A) (157 mg, 0.61 mmol) in 1,4-dioxane (1.0 mL) was added dropwise to 1-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,2,3,4-tetrahydroquinoxaline (25F) (167 mg, 0.61 mmol), K2CO3 (207 mg, 1.52 mmol), tetrabutylammonium bromide (19.5 mg, 0.061 mmol), and dichlorobis(triphenylphosphine)palladium(II) (17.9 mg, 0.024 mmol) in 1,4-dioxane (2.0 mL) and water (1.0 mL) at rt. The mixture was microwave (150 W) heated to 100° C. for 50 minutes, cooled to 20° C., diluted with water and extracted with EtOAc. The organic phases were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude material was purified by flash column chromatography on silica gel eluting with a gradient of PE:EtOAc 100:0-70:30, to provide 76 mg (38%) of the desired product tert-butyl 6-(1-methyl-1,2,3,4-tetrahydroquinoxalin-6-yl)picolinate (25G): 1H NMR (300 MHz, MeOD) δ 7.84-7.78 (3H, m), 7.35 (1H, d), 7.30 (1H, d), 6.62 (1H, d), 3.41 (2H, t), 3.31 (2H, t), 2.92 (3H, bs), 1.64 (9H, s).

Provenance & Evidence