Reaktion #54098

Reaktionsgleichung

2-amino-3-nitrophenol

HCl

sodium nitrite

→

2-chloro-3-nitrophenol

Ausbeute 62.0%

Lösungsmittel

H2SO4

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction was stirred for 18 hours
2. 2
   FiltrationThe heterogeneous mixture was filtered
3. 3
   Waschenwashed with water
4. 4
   ExtraktionThe filtrate was extracted three times with 70 mL portions of EtOAc
5. 5
   SonstigeEvaporation of EtOAc extractions

Vorschrift

To a suspension of 2-amino-3-nitrophenol (10 g, 65 mmol) in concentrated HCl (10 mL) at 0° C., sodium nitrite (5.1 g, 73.3 mmol) in water (60 mL) was added dropwise. After stirring for 30 minutes at 0° C., CuCl (12.8 g, 130 mmol) in 10% H2SO4 (3 mL) was added and the reaction was stirred for 18 hours. The heterogeneous mixture was filtered and washed with water. The filtrate was extracted three times with 70 mL portions of EtOAc. Evaporation of EtOAc extractions afforded 7 grams (62% yield) of pure 2-chloro-3-nitrophenol. 2-Chloro-3-nitrophenol (6 g, 35 mmol) was dissolved in methanol (100 mL) and treated with ammonium chloride (9.4 g, 175.7 mmol) and zinc dust (46 g, 702.8 mmol). The resulting mixture was refluxed for one hour. After filtration and evaporation, 2-chloro-3-aminophenol was collected (4.5 g, 90% yield) as a purple solid. To a suspension of 2-chloro-3-aminophenol (4.5 g, 31 mmol) in concentrated HCl (10 mL) at 0° C. was added dropwise sodium nitrite (2.5 g, 35 mmol) in water (50 mL). After stirring for 30 minutes at 0° C., KI (10.4 g, 63 mmol) in 10% H2SO4 (3 mL) was added dropwise. The reaction was stirred at room temperature for 2 hours, then filtered, extracted with EtOAc, and concentrated in vacuo to afford 2-chloro-3-iodophenol as a dark purple solid (6 g, 75% yield).

Quelle