HCID 23402488, compound → HCID 23402483, compound

5-butyl-4-nitro-1H-pyrazol-3-carboxylic acid amide (3.1 g, 17.0 mmol) and 10% palladium on carbon (600 mg) in ethanol (50 ml) were stirred under hydrogen (50 psi) at room temperature for 18 hours. The reaction mixture was filtered and the solid was washed with methanol (50 ml), dichloromethane (50 ml), ethanol (50 ml) and ethyl acetate (50 ml). The filtrate was concentrated under reduced pressure and the residue was purified by flash column chromatography on silica gel eluting with a solvent gradient of dichloromethane:methanol (95:5 changing to 90:10, by volume) to give 4-amino-5-butyl-1H-pyrazol-3-carboxylic acid amide (2.37 g) as an an orange solid. 1H NMR (400 MHz, DMSO-D6): δ=12.24-12.32 (1H, brs), 7.02-7.14 (1H, brs), 6.80-6.95 (1H, brs 4.28-4.46 (2H, brs), 2.39-2.50 (2H, t, partially masked by solvent), 1.45-1.56 (2H, quin), 1.22-1.35 (2H, sext), 0.83-0.90 ppm. LRMS (electrospray): m/z [M−H]+ 181, [2M−H]+ 363. Anal. Found C, 52.58; H, 7.80; N, 30.56. C8H14N4O requires C, 52.73; H, 7.74; N, 30.75%.

1. filtrationThe reaction mixture was filtered
2. washthe solid was washed with methanol (50 ml), dichloromethane (50 ml), ethanol (50 ml) and ethyl acetate (50 ml)
3. concentrationThe filtrate was concentrated under reduced pressure
4. customthe residue was purified by flash column chromatography on silica gel eluting with a solvent gradient of dichloromethane:methanol (95:5 changing to 90:10, by volume)

ORD record

ord-a9800a56dbdf46c68aa97958bef6649d

Source dataset

uspto-grants-2005_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06967204B2