반응 #7249

반응 방정식

3-cyano-2-chloro-pyridine

methylboronic acid

K2CO3

→

desired product

수율 46.1%

3-cyano-2-picoline

수율 46.1%

용매

dioxane

CH2Cl2

반응 조건

후처리

1. 1
   온도at reflux over the weekend
2. 2
   여과filtered through Celite
3. 3
   세척washing the cake with CH2Cl2 and MeOH
4. 4
   농축The filtrate was concentrated in vacuo
5. 5
   기타purified by column chromatography on silica gel (Hexanes/ethyl acetate, 9:1

실험 절차

To a mixture of 3-cyano-2-chloro-pyridine (422 mg, 3.05 mmol), methylboronic acid (209 mg, 3.49 mmol) and K2CO3 (1.22 g, 8.83 mmol) in degassed dioxane (5 mL) under argon was added Pd(PPh3)4 (222 mg, 0.19 mmol) and the mixture stirred at reflux over the weekend. The reaction was cooled to room temperature, diluted with CH2Cl2 (20 mL) and filtered through Celite, washing the cake with CH2Cl2 and MeOH. The filtrate was concentrated in vacuo and purified by column chromatography on silica gel (Hexanes/ethyl acetate, 9:1 then 4:1) to afford the desired product (166 mg, 46%) as a white solid. 1H NMR (CDCl3): δ 2.78 (s, 3H), 7.25 (dd, 1H, J=9, 6 Hz), 7.90 (dd, 1H, J=6, 3 Hz), 8.69 (d, 1H, J=3 Hz).

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