Methyl iodide → 1,5-Dimethyl-4-nitro-1H-pyrazole

Temperature

60 °C

To a solution of 3-methyl-4-nitro-1H-pyrazole (4.01 g, 31.6 mmol) in DMF (60 mL) were added CH3I (8.93 g, 63.0 mmol) and K2CO3 (8.73 g, 63.2 mmol). The reaction mixture was stirred at 60° C. in a sealed tube overnight and concentrated in vacuo. The residue was diluted with water (50 mL), and extracted with EtOAc (50 mL×3). The combined organic phases were washed with brine (50 mL), dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (EtOAc/PE (v/v)=1/2) to give the title compound as a beige solid (1.01 g, 22.7%).

1. concentrationconcentrated in vacuo
2. additionThe residue was diluted with water (50 mL)
3. extractionextracted with EtOAc (50 mL×3)
4. washThe combined organic phases were washed with brine (50 mL)
5. dry with materialdried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was purified by silica gel column chromatography (EtOAc/PE (v/v)=1/2)

ORD record

ord-fbdc1fc1d75a40f989be6c945d066829

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403801B2