반응 #2162351

반응 방정식

benzoyl peroxide

Benzoyl peroxide

2-chloro-3-fluoro-5-methylpyridine

NBS

→

5-(bromomethyl)-2-chloro-3-fluoropyridine

용매

CCl4

반응 조건

후처리

1. 1
   workup.WAITthe stirring was continued for 1 hour
2. 2
   여과filtered
3. 3
   세척the solid was washed with dichloromethane
4. 4
   세척The combined filtrates was washed with water
5. 5
   건조dried over anhydrous sodium sulfate
6. 6
   농축concentrated on a rotary evaporator
7. 7
   기타The crude product was purified by silica gel column chromatography (hexane/ethyl acetate)

실험 절차

Benzoyl peroxide (100 mg, 41 mmol) was added to a refluxing mixture of 2-chloro-3-fluoro-5-methylpyridine (5.0 g, 34.35 mmol) and NBS (6.73 g, 37.79 mmol) in CCl4 (180 mL). After stirring the mixture for 15 minutes, an additional amount of benzoyl peroxide (400 mg, 1.65 mmol) was added in four portions over a period of 1 hour and the stirring was continued for 1 hour. The reaction mixture was cooled to room temperature, filtered and the solid was washed with dichloromethane. The combined filtrates was washed with water, dried over anhydrous sodium sulfate and concentrated on a rotary evaporator. The crude product was purified by silica gel column chromatography (hexane/ethyl acetate) to afford 5-(bromomethyl)-2-chloro-3-fluoropyridine: 1H NMR (400 MHz, CDCl3) δ 8.23 (d, J=2.0 Hz, 1H), 7.55 (dd, J=2.0, 8.8 Hz, 1H), 4.45 (s, 2H).

출처