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

HRID 595700Notes

Reaction equation

[Br:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][C:8]2[C:4](=[C:5]([C:22]#[N:23])[N:6]([C:15]3[CH:20]=[CH:19][C:18]([F:21])=[CH:17][CH:16]=3)[N+:7]=2[O-])[CH:3]=1.P(Cl)(Cl)Cl>C(Cl)(Cl)Cl>[Br:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][C:8]2[C:4](=[C:5]([C:22]#[N:23])[N:6]([C:15]3[CH:16]=[CH:17][C:18]([F:21])=[CH:19][CH:20]=3)[N:7]=2)[CH:3]=1

Participants

Conditions

Temperature: 60 °C

Procedure

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.

Workup

extractionextracted into DCM (2×80 mL)
concentrationThe organic layer was concentrated
additionethanol was added to the residue
filtrationAfter filtration, 5-bromo-2-(4-fluorophenyl)-6-nitro-2H-indazole-3-carbonitrile
customwas collected as solid (4.3 g, 91%)

Sources & evidence

ORD record: ord-f467ba6cff3a4cf0a2d7936576d97286
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09243002B2

Reaction notes

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