Chlorosulfonic acid → 1,5-Dimethyl-3-(trifluoromethyl)-1H-pyrazole-4-sulfonyl chloride
Reaction equation
[Cl:1][S:2]([OH:5])(=O)=[O:3].[CH3:6][N:7]1[C:11]([CH3:12])=[CH:10][C:9]([C:13]([F:16])([F:15])[F:14])=[N:8]1>>[CH3:6][N:7]1[C:11]([CH3:12])=[C:10]([S:2]([Cl:1])(=[O:5])=[O:3])[C:9]([C:13]([F:14])([F:16])[F:15])=[N:8]1Participants
Conditions
- Temperature
- 110 °C
Procedure
To 53 mls of chlorosulfonic acid at 10° C. was added dropwise over fifteen minutes 1,5-dimethyl-3-(trifluoromethyl)pyrazole (24.0 grams). No significant exotherm resulted and after 15 minutes the cooling bath was removed and the reaction was heated to 110° C. for three hours. After standing overnight, the reaction was heated to 110° C. for an additional four hours and allowed to cool to 50° C. Then 19.0 g of thionyl chloride was dropwise over fifteen minutes. The reaction was then heated to 80° C. for twenty minutes and 110° C. for one hour. After cooling, the reaction was cautiously added to 600 g of ice. The aqueous phase was extracted with two 250 ml portions of ether. The combined organic extracts were dried with MgSO4 and concentrated under reduced pressure to yield 7.8 g of the desired product as a tan oil.
Workup
- customNo significant exotherm resulted and after 15 minutes the cooling bath
- customwas removed
- temperaturethe reaction was heated to 110° C. for an additional four hours
- temperatureto cool to 50° C
- waitThen 19.0 g of thionyl chloride was dropwise over fifteen minutes
- temperatureThe reaction was then heated to 80° C. for twenty minutes and 110° C. for one hour
- temperatureAfter cooling
- additionthe reaction was cautiously added to 600 g of ice
- extractionThe aqueous phase was extracted with two 250 ml portions of ether
- dry with materialThe combined organic extracts were dried with MgSO4
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-81dc4316fa4548eca0273b9248602dfd
- Source dataset
- uspto-grants-1996_03
- Patent number
- US05500405
Reaction notes
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