Reaction #7766

Reaction equation

2-(4-Fluorophenyl)-6-methoxy-3-(2-methylsulfanyl-pyrimidin-4-yl)-6,7-dihydro-5H-pyrazolo[1,2-a]pyrazol-1-one

3-Chloroperbenzoic acid

sodium bisulfite

3-chloroperbenzoic acid

→

mixture

2-(4-fluorophenyl)-6-methoxy-3-(2-methanesulfonyl-pyrimidin-4-yl)-6,7-dihydro-5H-pyrazolo[1,2-a]pyrazol-1-one

Solvents

dichloromethane

Conditions

Workup

1. 1
   workup.WAITAfter 10 minutes
2. 2
   OtherThe layers are separated
3. 3
   Extractionthe aqueous layer extracted with dichloromethane (2×50 mL)
4. 4
   WashThe combined organic layers are washed with a saturated aqueous solution of sodium bicarbonate (2×50 mL)
5. 5
   Dryingdried over sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated in vacuo

Procedure

2-(4-Fluorophenyl)-6-methoxy-3-(2-methylsulfanyl-pyrimidin-4-yl)-6,7-dihydro-5H-pyrazolo[1,2-a]pyrazol-1-one, 49, (1.10 g, 2.95 mmol) is diluted with dichloromethane (60 mL). 3-Chloroperbenzoic acid (662 mg of ˜77% purity, 2.95 mmol) is added all at once to the yellow suspension. After 20 min, additional 3-chloroperbenzoic acid (240 mg, 1.07 mmol) is added. After 10 minutes, the clear, yellow reaction solution is poured in a 10% aqueous solution of sodium bisulfite (60 mL). The layers are separated and the aqueous layer extracted with dichloromethane (2×50 mL). The combined organic layers are washed with a saturated aqueous solution of sodium bicarbonate (2×50 mL), dried over sodium sulfate, filtered and concentrated in vacuo to afford 948 mg of a mixture of the corresponding sulfoxide and sulfone as a yellow solid. Used as is for next step.

Source