5-ethyl-1-(2-methoxyethyl)-4-nitro-1H-pyrazole-3-carboxamide → 4-amino-5-ethyl-1-(2-methoxyethyl)-1H-Pyrazole-3-carboxamide

A mixture of 5-ethyl-1-(2-methoxyethyl)-4-nitro-1H-pyrazole-3-carboxamide (20 g, 82.6 mMol) and 5%Pd/C (1 g) in methanol (200 mL) was pressurised at 50 psi/25° C. in a sealed vessel and stirred for 15 hours. At the end of the reaction the mixture was filtered through arbocel and the filter cake was washed with methanol. The methanolic solution was distilled at atmospheric pressure and replaced with ethyl acetate to a final volume of 100 mL. The cooled mixture was granulated at ambient temperature for 2 h filtered and washed with ethyl acetate (20 mL) to afford 4-amino-5-ethyl-1-(2-methoxyethyl)-1H-pyrazole-3-carboxamide as a white crystalline solid, 15 g, 88%. m.p.=131° C. Found: C, 50.75; H, 7.62; N, 26.38. C9H16N4O2 requires C, 50.94; H, 7.55; N, 26.42%.

1. customwas pressurised at 50 psi/25° C. in a sealed vessel
2. customAt the end of the reaction the mixture
3. filtrationwas filtered through arbocel
4. washthe filter cake was washed with methanol
5. distillationThe methanolic solution was distilled at atmospheric pressure
6. waitThe cooled mixture was granulated at ambient temperature for 2 h
7. filtrationfiltered
8. washwashed with ethyl acetate (20 mL)

ORD record

ord-e67bc94a9a574addb96b61d708c3dd29

Source dataset

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06699991B2