반응 #587918

반응 방정식

water

2-amino-5-bromo-3-iodopyridine

isopropenylboronic acid pinacol ester

sodium carbonate

→

5-bromo-3-(prop-1-en-2-yl)pyridin-2-amine

용매

dimethylformamide

ethyl acetate

반응 조건

후처리

1. 1
   온도After cooling to room temperature
2. 2
   여과suction-filtered
3. 3
   기타to remove some insoluble black precipitate
4. 4
   기타After separation
5. 5
   추출the aqueous layer was back-extracted with 100 mL ethyl acetate
6. 6
   건조The combined organic extracts were dried over magnesium sulfate
7. 7
   여과filtered
8. 8
   농축concentrated to 5.87 g brown oil
9. 9
   기타The crude product was purified by silica gel chromatography (
10. 10
    세척eluting with a 10-50% ethyl acetate in hexanes gradient),
11. 11
    기타to give B-78-2 (2.5501 g, 75.3%) as a tan solid

실험 절차

A solution of 2-amino-5-bromo-3-iodopyridine B-78-1 (4.75 g, 15.9 mmol), isopropenylboronic acid pinacol ester (3.28 mL, 2.94 g, 17.5 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]-palladium(II) dichloride dichloromethane complex (1:1) (295 mg, 0.403 mmol) in dimethylformamide (48 mL) was treated with 24 mL of 2.0 M aqueous sodium carbonate solution. The resulting biphasic mixture was stirred under argon in a 65° C. oil bath for 6 hours. After cooling to room temperature, the mixture was diluted with 200 mL ethyl acetate and 75 mL deionized water, then suction-filtered to remove some insoluble black precipitate. After separation, the aqueous layer was back-extracted with 100 mL ethyl acetate. The combined organic extracts were dried over magnesium sulfate, filtered, and concentrated to 5.87 g brown oil. The crude product was purified by silica gel chromatography (eluting with a 10-50% ethyl acetate in hexanes gradient), to give B-78-2 (2.5501 g, 75.3%) as a tan solid.

출처