反应详情

PdCl2(PPh3)2 (0.7 g, 1.03 mmol, 0.05 eq.) was added to a solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester (6.3 g, 20.5 mmol, 1.0 eq.) in THF (120 mL) under nitrogen. To this was added 3-bromoisonicotinic acid methyl ester (4.4 g, 20.5 mmol, 1.0 eq.). This was followed by the addition of a solution of Na2CO3 (8.7 g, 82.1 mmol, 4.0 eq.) in water (41 mL). The resulting solution was stirred for 14 hours while the temperature was maintained at reflux in an oil bath. The resulting solution was diluted with EtOAc (100 mL), and washed with saturated aqueous NaCl (2×100 mL). The organic layer was dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was applied onto a silica gel column and eluted with EtOAc/PE (1:10) to yield 3′,6′-dihydro-2′H-[3,4′]bipyridinyl-4,1′-dicarboxylic acid 1′-t-butyl ester 4-methyl ester (5.6 g) as a yellow oil.

1. temperaturewas maintained
2. temperatureat reflux in an oil bath
3. washwashed with saturated aqueous NaCl (2×100 mL)
4. dry with materialThe organic layer was dried over anhydrous Na2SO4
5. concentrationconcentrated under vacuum
6. washeluted with EtOAc/PE (1:10)