تفاعل #2336544

معادلة التفاعل

4-chloro-2-fluoro-5-methoxyaniline

sodium nitrite

Methylene chloride

bromide

→

1-bromo-4-chloro-2-fluoro-5-methoxybenzene

المردود 49.0%

المذيبات

ethyl acetate

—

hexanes

HBr

water

ظروف التفاعل

المعالجة

1. 1
   ترشيحThe reaction mixture was filtered through a bed of celite and
2. 2
   استخلاصextracted with methylene chloride (2×100 mL)
3. 3
   تجفيفthe combined organic phases were dried (sodium sulfate)
4. 4
   تركيزconcentrated

الإجراء التجريبي

A solution of 4-chloro-2-fluoro-5-methoxyaniline (25.0 g, 0.143 mol) in 10% HBr (250 mL) was cooled to 0° C. and a solution of sodium nitrite (15.0 g, 0.218 mol) in water (20 mL) was slowly added. Methylene chloride (50 mL) and curpric bromide (30.0 g, 0.244 mol) were added slowly and then the mixture was warmed to ambient temperature and stirred for 1 hour. The reaction mixture was filtered through a bed of celite and extracted with methylene chloride (2×100 mL) and the combined organic phases were dried (sodium sulfate) and concentrated. Chromatography of the dark oil (5% ethyl acetate in hexanes) gave 1-bromo-4-chloro-2-fluoro-5-methoxybenzene (16.6 g, 0.070 mol): 1H NMR (CDCl3): δ 7.20 (m, 1H) 7.05 (dd, 1H), 4.00 (s, 3H).

المصدر