Hydrogen Sulfide → 1-[2-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]acetyl]-4-piperidinecarbothioamide

Participants

Reaction Conditions

Reaction Steps

Hydrogen sulfide gas was passed into a solution of 1-[2-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]acetyl]-4-piperidinecarbonitrile (i.e. the product of Example 8, Step B) (9.0 g, 30 mmol) and diethanolamine (3.15 g, 30 mmol) in N,N-dimethylformamide (15 mL) at 50° C. in a flask equipped with dry-ice condenser. The hydrogen sulfide feed was stopped when the reaction mixture became saturated with hydrogen sulfide, as indicated by condensation on the cold-finger. The reaction mixture was stirred for an additional 30 minutes at 50° C. Then excess hydrogen sulfide gas was sparged into the scrubber by a subsurface nitrogen flow, and water (70 mL) was gradually added. The reaction mixture was cooled to 5° C., filtered, and washed with water (2×30 mL). The filter cake was dried at 50° C. in a vacuum-oven to give 8.0 g of the title compound as a solid, melting at 185-186° C.

Provenance & Evidence