تفاعل #2336551

معادلة التفاعل

sodium iodide

N-pivaloyl-2-bromo-4-chloro-3-methoxyaniline

hydrochloric acid

sodium

sodium nitrite

→

2-bromo-4-chloro-1-iodo-3-methoxybenzene

المردود 50.0%

المذيبات

water

methylene chloride

dioxane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe solution heated
2. 2
   درجة الحرارةunder reflux for 2 hours
3. 3
   درجة الحرارةAfter the solution was cooled the pH
4. 4
   استخلاصextracted with ethyl ether (2×50 mL)
5. 5
   غسيلThe combined extracts were washed with brine
6. 6
   تجفيفdried (sodium sulfate)
7. 7
   تركيزconcentrated
8. 8
   workup.DISSOLUTIONThe crude aniline was dissolved in 2N hydrochloric acid
9. 9
   workup.STIRRINGstirred for 20 minutes
10. 10
    استخلاصThe solution was then extracted with methylene chloride (2×25 mL)
11. 11
    غسيلthe combined extracts washed with brine
12. 12
    تجفيفdried (sodium sulfate)
13. 13
    تركيزconcentrated
14. 14
    أخرىThe residue was purified by chromatography (hexanes)

الإجراء التجريبي

A solution of N-pivaloyl-2-bromo-4-chloro-3-methoxyaniline (3.7 g, 1.2 mmol) in dioxane (35 mL) was treated with concentrated hydrochloric acid (35 mL) and the solution heated under reflux for 2 hours. After the solution was cooled the pH was adjusted to 10 by addition of sodium hyrdroxide (50% solution) and extracted with ethyl ether (2×50 mL). The combined extracts were washed with brine, dried (sodium sulfate) and concentrated. The crude aniline was dissolved in 2N hydrochloric acid and sodium nitrite (750 mg, 11 mmol) was added and the solution stirred for 20 minutes. This solution was poured into a vigorously stirred solution of sodium iodide (3.3 g, 22 mmol) in water (20 mL) and methylene chloride (30 mL) and stirred for 20 minutes. The solution was then extracted with methylene chloride (2×25 mL) and the combined extracts washed with brine, dried (sodium sulfate) and concentrated. The residue was purified by chromatography (hexanes) to give 2-bromo-4-chloro-1-iodo-3-methoxybenzene (1.5 g, 0.6 mmol): LC/MS (m/z=267).

المصدر