تفاعل #2336547

معادلة التفاعل

1-bromo-4-chloro-2-fluorobenzene

LDA

dimethyldisulfide

→

1-bromo-4-chloro-2-fluoro-3-(methylthio)benzene

المردود 94.0%

المذيبات

THF

THF

THF

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONAfter addition
2. 2
   درجة الحرارةcooled to −50° C.
3. 3
   درجة الحرارةthe mixture was warmed to ambient temperature
4. 4
   أخرىThe reaction was quenched with water (200 mL)
5. 5
   استخلاصextracted with ethyl acetate (2×150 mL)
6. 6
   تجفيفthe combined organic phases dried (sodium sulfate)
7. 7
   تركيزconcentrated
8. 8
   أخرىThe residual red oil was purified by chromatography (5% ethyl acetate in hexanes)

الإجراء التجريبي

A solution of 1-bromo-4-chloro-2-fluorobenzene (20.4 g, 0.100 mol) in THF (50 mL) was slowly added to LDA (0.125 mol) in THF (600 mL) at −50° C. After addition, the solution was warmed to −20° C. and then cooled to −50° C. and a solution of dimethyldisulfide (18.8 g, 0.20 mol) in THF (50 mL) was slowly added and the mixture was warmed to ambient temperature. The reaction was quenched with water (200 mL) and extracted with ethyl acetate (2×150 mL) and the combined organic phases dried (sodium sulfate) and concentrated. The residual red oil was purified by chromatography (5% ethyl acetate in hexanes) to give 1-bromo-4-chloro-2-fluoro-3-(methylthio)benzene (23.9 g, 0.094 mol): 1H NMR (CDCl3): δ 7.40 (m, 1H), 7.15 (dd, 1H), 2.50 (s, 3H).

المصدر