N-bromobutanimide → 4-bromo-5-chloro-1,3-dimethyl-1H-pyrazole

HRID 2095690Notes

Reaction equation

HRID 2095690 reaction equation
[Cl:1][C:2]1[N:6]([CH3:7])[N:5]=[C:4]([CH3:8])[CH:3]=1.C1C(=O)N([Br:16])C(=O)C1>C(Cl)(Cl)(Cl)Cl>[Br:16][C:3]1[C:4]([CH3:8])=[N:5][N:6]([CH3:7])[C:2]=1[Cl:1]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 5215075-Chloro-1,3-dimethylpyrazole

Product 1

HCID 197442234-bromo-5-chloro-1,3-dimethyl-1H-pyrazoleYield 52.2%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

A solution of 5-chloro-1,3-dimethyl-1H-pyrazole (0.500 g, 3.83 mmol) in carbon tetrachloride (2.0 mL) was charged with NBS (0.750 g, 4.21 mmol) and stirred at rt for 16 h. The reaction mixture was charged with silica gel and purified by chromatography on silica gel [ISCO Combiflash, 12 g cartridge, eluting with 100% heptane 10% EtOAc in heptane]. This resulted in 419 mg, 52% yield of the title compound as a white solid. 1H NMR (400 MHz, CDCl3): δ=2.23 (s, 3H), 3.81 (s, 3H). MS (ES+): m/z 208.96, 210.93 (76/24) [MH+]. HPLC: tR=2.62 min (polar—5 min, ZQ3).

Workup

  1. additionThe reaction mixture was charged with silica gel
  2. custompurified by chromatography on silica gel [ISCO Combiflash, 12 g cartridge, eluting with 100% heptane 10% EtOAc in heptane]

Sources & evidence

ORD record
ord-13e0708973f44c2b957784d2ae99f458
Source dataset
uspto-grants-2013_05
Patent number
US08445510B2

Reaction notes

Loading…