Reaktion #7063

Reaktionsgleichung

hydrochloric acid

2,4-dibromoaniline

Copper cyanide

tert-butylnitrite

→

title compound

Ausbeute 31.0%

2,4-Dibromobenzonitrile

Ausbeute 31.0%

Lösungsmittel

dimethylsulfoxide

dimethylsulfoxide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto form a clear solution
2. 2
   workup.ADDITIONAfter the addition
3. 3
   TemperaturFive minutes later, the reaction mixture is cooled to ambient temperature
4. 4
   Extraktionbefore being extracted with ethyl acetate/hexane (1:1; 2×300 mL)
5. 5
   WaschenThe combined organic layers are washed with water (100 mL) and brine (100 mL)
6. 6
   Sonstigedried
7. 7
   Einengenconcentrated in vacuo
8. 8
   Sonstigechromatographed on silica (0–5% ethyl acetate in hexane)

Vorschrift

Copper cyanide (2.32 g, 25.9 mmol) is added to stirred anhydrous dimethylsulfoxide (50 mL) at 60° C. to form a clear solution, followed by the addition of tert-butylnitrite (7.1 mL, 59.7 mmol) all at once. A solution of 2,4-dibromoaniline 21 (5.0 g, 19.9 mmol) in anhydrous dimethylsulfoxide (30 mL) is added dropwise, via cannula, to the mixture. After the addition is complete, the reaction mixture is allowed to stir for 1 hr. After being cooled to 45° C., the mixture is slowly treated with 5N hydrochloric acid (50 mL). Five minutes later, the reaction mixture is cooled to ambient temperature before being extracted with ethyl acetate/hexane (1:1; 2×300 mL). The combined organic layers are washed with water (100 mL) and brine (100 mL), dried, concentrated in vacuo, and then chromatographed on silica (0–5% ethyl acetate in hexane) to give the title compound (1.61 g, 31% yield). FD(+)MS m/z 259, (M+) consistent with 2 Br.

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