Reaktion #522785

Reaktionsgleichung

sodium thiosulphate

5-methyl-anthranilic acid

potassium iodide

hydrochloric acid

sodium nitrite

hydrochloric acid

→

2-iodo-5-methyl-benzoic acid

Lösungsmittel

water

water

—

3-N

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThere is added dropwise
2. 2
   workup.STIRRINGThe mixture is then stirred for a further 30 minutes at room temperature and for 2 hours
3. 3
   Temperaturunder reflux
4. 4
   TemperaturThe mixture is then cooled

Vorschrift

20 g of 5-methyl-anthranilic acid are suspended in 200 ml of 3-N hydrochloric acid at 0° C. There is added dropwise thereto with stirring a solution of 10 g of sodium nitrite and 20 ml of water and the mixture is stirred for 25 minutes at 0° C. A solution of 26.5 g of potassium iodide, 30 ml of 3-N hydrochloric acid and 30 ml of water is then added dropwise at 5°-10° C. The mixture is then stirred for a further 30 minutes at room temperature and for 2 hours under reflux. The mixture is then cooled, sodium thiosulphate is added until the solution is yellow (5 g) and the crystalline 2-iodo-5-methyl-benzoic acid obtained is filtered under suction and washed with water until neutral. The crude acid is dissolved in ether, washed well with sodium thiosulphate solution and water, dried over sodium sulphate and evaporated. There are obtained light-brown crystals of melting point 100°-112° C.

Quelle