Benzoyl Peroxide → 3-(Bromomethyl)-1H-indazole, N1-BOC protected

HRID 1804637Notes

Reaction equation

HRID 1804637 reaction equation
[CH3:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[N:3]=1.[Br:18]NC(=O)CCC(N)=O.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>C(Cl)(Cl)(Cl)Cl>[Br:18][CH2:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[N:3]=1

Participants

5

Reactant 3

HCID 7187Benzoyl PeroxideHCID 9834204N-BromosuccinamideHCID 10775939tert-Butyl 3-methyl-1H-indazole-1-carboxylate

Product 1

HCID 108049513-(Bromomethyl)-1H-indazole, N1-BOC protectedYield 76.1%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a mixture of compound from step A (2 g, 8.61 mmol) and N-bromosuccinamide (1.84 g, 10.33 mmol) in carbon tetrachloride (50 ml) was added benzoyl peroxide (209 mg, 0.86 mmol) and the resulting mixture heated at reflux for 4 h. The reaction mixture cooled and filtered through celite, and filtrate evaporated. The residue purified by MPLC (Biotage Horizon: FLASH 40+s) eluent: 100% Hexanes (190 ml), gradient rising from 100% hexanes to 10% EtOAc in Hexanes (1000 ml), then 10% EtOAc in Hexanes (250 ml) to afford the title compound 2.04 g (76%). 1H NMR (CDCl3): 1.75 (s, 9H), 4.82 (s, 2H), 7.39 (m, 1H), 7.58 (m, 1H), 7.87 (d, J 8.0 Hz, 1H), 8.15 (d, J 8.5 Hz, 1H).

Workup

  1. temperaturethe resulting mixture heated
  2. temperatureat reflux for 4 h
  3. temperatureThe reaction mixture cooled
  4. filtrationfiltered through celite, and filtrate
  5. customevaporated
  6. customThe residue purified by MPLC (Biotage Horizon: FLASH 40+s) eluent

Sources & evidence

ORD record
ord-410901ee1ec94223b8a104533ed5b780
Source dataset
uspto-grants-2013_01
Patent number
US08354403B2

Reaction notes

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