Sodium Hydroxide → HCID 21464385, compound

Participants

Reaction Steps

Trifluoromethanesulfenyl chloride (11.6 g, 85.0 mmol) was added to a solution of 3-amino-1-methylpyrazole (8.0 g, 82.4 mmol) in 150 mL of dichloromethane with stirring at a rate such that the temperature did not rise above 5° C. When the addition was complete the mixture was allowed to warm to ambient temperature and stir for 18 hours and was then purged with nitrogen gas for 1 hour to remove any unreacted trifluoromethanesulfenyl chloride. The solid that formed during the reaction was collected by filtration and the filtrate was concentrated by evaporation under reduced pressure to obtain additional solids. The combined solids were dissolved in water and the solution was basified with 1N aqueous sodium hydroxide. The resulting mixture was extracted with dichloromethane (2×100 mL) and the extracts were combined, dried over magnesium sulfate, and filtered. The filtrate was concentrated by evaporation under reduced pressure to obtain a solid residue that appeared to be a mixture of two compounds. This solid was recrystalized from methylcyclohexane to obtain 16.2 g (40 percent of theory) of the title compound as a yellow solid melting at 138°-140° C. The impurity was identified as 1-methyl-3-((trifluoromethanesulfenyl)amino)-4-(trifluoromethythio)pyrazole.

Provenance & Evidence