Water → 1-(Methylsulfonyl)-1H-pyrazol-4-amine

To a solution of 4-nitro-1H-pyrazole (250 mg, 2.2 mmol) in DCM (5 mL) were added triethylamine (0.46 mL, 1.5 eq) and methanesulfonyl chloride (0.20 mL, 1.2 eq). After stirring for 1 h at rt, water was added and the aqueous phase extracted with DCM. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. The residue was dissolved in 5 mL methanol and palladium on carbon added under an inert atmosphere. The reaction mixture was stirred overnight at rt under an hydrogen atmosphere. The resulting mixture was filtered through Celite and the filtrate concentrated in vacuo to give 1-(methylsulfonyl)-1H-pyrazol-4-amine as a brown oil (0.34 g, 2.1 mmol, 96%).

1. extractionthe aqueous phase extracted with DCM
2. dry with materialThe combined organic phases were dried over sodium sulfate
3. concentrationconcentrated in vacuo
4. dissolutionThe residue was dissolved in 5 mL methanol
5. additionpalladium on carbon added under an inert atmosphere
6. stirringThe reaction mixture was stirred overnight at rt under an hydrogen atmosphere
7. filtrationThe resulting mixture was filtered through Celite
8. concentrationthe filtrate concentrated in vacuo

ORD record

ord-467cf61835c04a5ab77d4c6a51b53b92

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09242987B2