4-Nitro-1-(oxan-2-yl)-1H-pyrazole-3-carbaldehyde → HCID 178480424, compound

Participants

Reaction Conditions

Reaction Steps

18 g of 4-nitro-1-(tetrahydropyran-2-yl)-1H-pyrazole-3-carbaldehyde and 664 mg of ferric chloride are added to a solution of 19.1 g of 4-fluoro-5-(4-methylperhydro-1,4-diazepin-1-yl)benzene-1,2-diamine in 406 mL of DMF. The reaction medium is stirred at 22° C. for 4 hours. After evaporation, the reaction crude is purified on a column 8 cm in diameter, with 3 kg of silica having a porosity of 0.063-0.2 mm. The elution is carried out with 2 L of pure dichloromethane and then 4 L of dichloromethane containing 10% of methanol, and then with dichloromethane containing 15% of methanol. 12 g of 5-fluoro-6-(4-methylperhydro-1,4-diazepin-1-yl)-2-[4-nitro-1-(tetrahydropyran-2-yl)-1H-pyrazol-3-yl]-1H-benzimidazole are isolated. 1H NMR (400 MHz, DMSO-d6, δ in ppm): 1.41 to 2.31 (m, 8H); 2.91 (s, 3H); from 3.22 to 3.67 (m, 8H); 3.72 (m, 1H); 3.99 (m, 1H); 5.69 (dd, J=2.5 and 9.5 Hz, 1H); 7.32 (d, J=8.0 Hz, 1H); 7.75 (d, J=12.0 Hz, 1H); 9.40 (s, 1H). EI mass spectrum: m/z=443: M+. —m/z=373: (M−C4H8N)+—m/z=289: (m/z=373—C5H8O)+—m/z=84: C5H8O+. (base peak)—m/z=57: C3H7N+.

Provenance & Evidence