反应详情

温度

75 °C

To a 5-L four-necked flask equipped with an overhead stirrer, a thermocouple and a condenser was charged with 2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (34b, 1120 mmol), 6-chloro-5-methylnicotinaldehyde (34c, 174.3 g, 1120 mmol), Pd(dppf)Cl2.CH2Cl2 (4.57 g, 5.6 mmol), K2CO3 (309.6 g, 2240 mmol), and iso-propyl acetate (1120 mL)/water (1120 mL). The mixture was stirred at 75° C. for 4 h, and cooled to 30° C. The organic layer was separated, washed with 10% NaCl (1120 g), and treated with activated charcoal (50 g) at 50° C. for 2 h before cooling to rt and filtered through Celite. Concentration of the filtrate to almost dryness afforded the crude 2′,3-dimethyl-[2,4′-bipyridine]-5-carbaldehyde (34d) as a brown oil.

1. customTo a 5-L four-necked flask equipped with an overhead stirrer
2. temperaturecooled to 30° C
3. customThe organic layer was separated
4. washwashed with 10% NaCl (1120 g)
5. additiontreated with activated charcoal (50 g) at 50° C. for 2 h
6. temperaturebefore cooling to rt
7. filtrationfiltered through Celite