Benzoyl Peroxide → 1-Acetyl-3-bromomethyl-6-fluoro-1H-indazole

HRID 1377511Notes

Reaction equation

[C:1]([N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[C:10]([F:13])[CH:11]=2)[C:6]([CH3:14])=[N:5]1)(=[O:3])[CH3:2].C1C(=O)N([Br:22])C(=O)C1.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>C(Cl)(Cl)(Cl)Cl>[C:1]([N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[C:10]([F:13])[CH:11]=2)[C:6]([CH2:14][Br:22])=[N:5]1)(=[O:3])[CH3:2]

Participants

Conditions

Temperature: 70 °C

Procedure

1-Acetyl-6-fluoro-3-methyl-1H-indazole (5.77 g, 33.1 mmol) in CCl4 (100 mL) was treated with NBS (3.64 g, 20 mmol) and benzoyl peroxide (0.388 g, 1.6 mmol) and the mixture was heated at 70° C. for 6 h. The mixture was concentrated and the residue quickly filtered through a plug of flash silica eluting with 2%→7% EtOAc in hexane to give the crude title compound (2.97 g, 65%) contaminated with traces of dibromide and starting material. This was conveniently used directly in subsequent reactions without further purification.

Workup

concentrationThe mixture was concentrated
filtrationthe residue quickly filtered through a plug of flash silica eluting with 2%→7% EtOAc in hexane

Sources & evidence

ORD record: ord-48669fab0a64479fa019f8dd00636f47
Source dataset: uspto-grants-1997_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05665732

Reaction notes

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