Reaktion #1917258

Reaktionsgleichung

4-Amino-2-methoxybenzoic acid methyl ester

sulfuric acid

potassium iodide

iodine

sodium nitrite

→

title product

Ausbeute 55.7%

4-Iodo-2-methoxybenzoic acid methyl ester

Ausbeute 55.7%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe suspension was cooled in an ice/salt water bath
2. 2
   Sonstigeremained close to 0° C
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Sonstigea homogeneous, yellow-green solution was obtained
5. 5
   ExtraktionThe reaction mixture was then extracted with ethyl acetate
6. 6
   Waschenwashed with 1 N sodium thiosulfate, 1 N sodium hydroxide and brine
7. 7
   TrocknenAfter drying over anhydrous sodium sulfate the solution
8. 8
   Filtrationwas filtered
9. 9
   Einengenconcentrated in vacuo

Vorschrift

4-Amino-2-methoxybenzoic acid methyl ester (3.0 g, 16.6 mmol) was suspended in water (40 mL) and concentrated sulfuric acid (10 mL). The suspension was cooled in an ice/salt water bath, and an aqueous solution (10 mL) of sodium nitrite (1.26 g, 18.3 mmol) was added dropwise so that the temperature remained close to 0° C. After the addition, a homogeneous, yellow-green solution was obtained. An aqueous solution (60 mL) of potassium iodide (3.02 g, 18.2 mmol) and iodine (2.31 g, 9.1 mmol) was then added dropwise, and the reaction stirred for an additional 1 hour. The reaction mixture was then extracted with ethyl acetate, the organic extracts were combined and washed with 1 N sodium thiosulfate, 1 N sodium hydroxide and brine. After drying over anhydrous sodium sulfate the solution was filtered and concentrated in vacuo to give 2.7 g of the title product as an orange oil which was used in the next step.

Quelle