Réaction #157263

Équation de réaction

bromine

o-ethylphenol

sodium thiocyanate

sodium bromide

sodium bicarbonate

→

3-ethyl-4-hydroxy-phenyl thiocyanic acid

Rendement 93.0%

Solvants

methanol

methanol

Conditions de réaction

Traitement

1. 1
   Températureto warm up to room temperature
2. 2
   workup.STIRRINGstirred for another 4 hours at room temperature
3. 3
   workup.STIRRINGstirred for 10 min
4. 4
   ExtractionThe mixture was extracted with ethyl acetate (2×300 ml)
5. 5
   SéchageThe combined organic layer was dried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltrated
7. 7
   ConcentrationFiltrate was concentrated under reduced pressure
8. 8
   Autreto give a reddish-brown sticky liquid

Mode opératoire

To a 500 ml three-necked flask were added sequentially o-ethylphenol (5 g, 40.9 mmol), sodium thiocyanate (10 g, 123.3 mmol), sodium bromide (4.3 g, 41.79 mmol) and methanol (100 ml). The mixture was cooled to 0° C. in an ice bath and then a solution of bromine (2.6 ml, 50.6 mmol) in methanol (50 ml) was added dropwise thereinto. After 1 hour of stirring at 0° C., the mixture was allowed to warm up to room temperature and then stirred for another 4 hours at room temperature. A 200 ml saturated aqueous solution of sodium bicarbonate was added slowly to the reaction mixture and stirred for 10 min. The mixture was extracted with ethyl acetate (2×300 ml). The combined organic layer was dried over anhydrous magnesium sulfate, and filtrated. Filtrate was concentrated under reduced pressure to give a reddish-brown sticky liquid. Column chromatography was performed (silica-gel H: 300-400 mesh; petroleum ether/ethyl acetate=5:1 v/v) to obtain 6.8 g of 3-ethyl-4-hydroxy-phenyl thiocyanic acid (reddish-brown sticky liquid, yield: 93%).

Source