Reaction #1726700

Reaction equation

sodium thiosulfate

5-amino-2-(methylsulfanyl)-4-phenylthiazole

3-chloroperbenzoic acid

sodium bicarbonate

3-chloroperbenzoic acid

→

5-amino-2-(methylsulfonyl)-4-phenylthiazole

Yield 26.0%

Solvents

dichloromethane

dichloromethane

Conditions

Workup

1. 1
   Temperatureto warm to ambient temperature
2. 2
   workup.ADDITION1.4 mmol) was added portionwise
3. 3
   Extractionextracted three times into dichloromethane (total 100 ml)
4. 4
   WashThe combined organic phases were washed with saturated aqueous sodium bicarbonate and brine
5. 5
   Dryingdried over sodium sulfate
6. 6
   Concentrationconcentrated in vacuo
7. 7
   Otherto give a dark brown foam

Procedure

To 5-amino-2-(methylsulfanyl)-4-phenylthiazole (302 mg, 1.36 mmol) in dichloromethane (5.0 ml) was added portionwise 3-chloroperbenzoic acid (638 mg, 77% wt, 2.9 mmol) with cooling to 0° C. The mixture was diluted with dichloromethane (3.0 ml) and after 5 min allowed to warm to ambient temperature. After 3 hr a further quantity of 3-chloroperbenzoic acid (305 mg, 77% wt, 1.4 mmol) was added portionwise. After 20 hr the mixture was treated with sodium thiosulfate (2 ml, 1.0 M), poured into saturated aqueous sodium bicarbonate and extracted three times into dichloromethane (total 100 ml). The combined organic phases were washed with saturated aqueous sodium bicarbonate and brine, dried over sodium sulfate and concentrated in vacuo to give a dark brown foam. Flash chromatography on silica gel (ethyl acetate/hexanes) yielded pure 5-amino-2-(methylsulfonyl)-4-phenylthiazole (90 mg, 26%).

Source