Phosphorus oxychloride → 6-bromo-3-chloro-2-(4-fluorophenyl)-2H-indazole

HRID 1037559Notes

Reaction equation

HRID 1037559 reaction equation
[N:1]([C:4]1[CH:19]=[C:18]([Br:20])[CH:17]=[CH:16][C:5]=1[C:6]([NH:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=1)=O)=[N+]=[N-].O=P(Cl)(Cl)[Cl:23]>>[Br:20][C:18]1[CH:17]=[CH:16][C:5]2[C:4]([CH:19]=1)=[N:1][N:8]([C:9]1[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=1)[C:6]=2[Cl:23]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 866664212-azido-4-bromo-N-(4-fluorophenyl)-benzamide

Product 1

HCID 677760136-bromo-3-chloro-2-(4-fluorophenyl)-2H-indazoleYield 64%

Conditions

Temperature
95 °C

Procedure

A mixture of compound (xii) (6.44 g, 19.20 mmol) and POCl3 (50 mL) was heated at 95° C. for 6 h. The volatiles were removed under reduced pressure and the residue was basified by the addition of an ice-cold saturated solution of sodium carbonate. The solid obtained was filtered and dried (Na2SO4) to give the crude product which was purified by column chromatography on 100-200 mesh silica gel eluting with EtOAc/hexane (3-5%) to give 6-bromo-3-chloro-2-(4-fluorophenyl)-2H-indazole (xiii) (4 g, 64%) as a white solid. ESI-MS m/z calculated for [M+H]+: 326.95; found: 326.95.

Workup

  1. customThe volatiles were removed under reduced pressure
  2. additionthe residue was basified by the addition of an ice-cold saturated solution of sodium carbonate
  3. customThe solid obtained
  4. filtrationwas filtered
  5. dry with materialdried (Na2SO4)
  6. customto give the crude product which
  7. customwas purified by column chromatography on 100-200 mesh silica gel eluting with EtOAc/hexane (3-5%)

Sources & evidence

ORD record
ord-2123886c45aa41eb93bc7343ba371228
Source dataset
uspto-grants-2013_10
Patent number
US08546389B2

Reaction notes

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