反应详情

A mixture of 4,6-dichloro-2-methyl-nicotinic acid ethyl ester (1.2 g, 5.1 mmol), 2,6-diethyl-phenyl boronic acid (2.18 g, 12.2 mmol), sodium carbonate (2 M aqueous solution, 12.2 mL, 24.4 mmol), and Pd(PPh3)4 (284 mg, 0.26 mmol) is refluxed in toluene for 48 hours and then cooled to room temperature. The organic layer is separated and the aqueous layer is extracted with ethyl acetate (2×50 mL). The organic Layers are combined, dried, and solvent removed. The crude product is purified by flash column (hexanes/ethyl acetate 8:1) to give 4-chloro-6-(2,6-diethyl-phenyl)-2-methyl-nicotinic acid ethyl ester. 1H NMR: (CDCl3) 7.26 (t, 1H), 7.18 (s, 1H), 7.13 (d, 2H), 4.47 (q, 2H), 2.62 (s, 3H), 2.28 (q, 4H), 1.44 (t, 3H), 1.04 (t, 6H).

1. customThe organic layer is separated
2. extractionthe aqueous layer is extracted with ethyl acetate (2×50 mL)
3. customdried
4. customsolvent removed
5. customThe crude product is purified by flash column (hexanes/ethyl acetate 8:1)