Phosphorus trichloride → 5-bromo-2-(4-fluorophenyl)-6-nitro-2H-indazole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 5-bromo-3-cyano-2-(4-fluorophenyl)-6-nitro-2H-indazole 1-oxide (5.0 g, 0.013 mol) in chloroform (50 mL) was added phosphorus trichloride (5.0 mL, 0.057 mol) dropwise and the reaction mixture was heated to 60° C. for 1 h. Then the reaction mixture was poured into ice water and extracted into DCM (2×80 mL). The organic layer was concentrated, and ethanol was added to the residue. After filtration, 5-bromo-2-(4-fluorophenyl)-6-nitro-2H-indazole-3-carbonitrile was collected as solid (4.3 g, 91%). 1H-NMR (CDCl3, 400 MHz) δ 8.38 (s, 1H), 8.25 (s, 1H), 7.89˜7.91 (m, 2H), 7.33˜7.37 (m, 2H). MS (M+H)+: 361/363.

Provenance & Evidence