Réaction #54098

Équation de réaction

2-amino-3-nitrophenol

HCl

sodium nitrite

→

2-chloro-3-nitrophenol

Rendement 62.0%

Solvants

H2SO4

water

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source