1H-1,2,4-Triazole → 1-Bromo-3,3-dimethyl-4-fluoro-2-butanone

HRID 986192Notes

Reaction equation

HRID 986192 reaction equation
[F:1][CH2:2][C:3]([CH3:8])([CH3:7])[C:4](=[O:6])[CH3:5].[Br:9]Br.N1C=NC=N1.C(=O)([O-])[O-].[K+].[K+]>C(Cl)Cl.CC(C)=O>[F:1][CH2:2][C:3]([CH3:8])([CH3:7])[C:4](=[O:6])[CH2:5][Br:9]

Participants

7

Reactant 4

HCID 92571H-1,2,4-TriazoleHCID 11430Potassium CarbonateHCID 24408BromineHCID 130194414-Fluoro-3,3-dimethylbutan-2-one

Product 1

HCID 130194421-Bromo-3,3-dimethyl-4-fluoro-2-butanoneYield 99.9%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 6344DichloromethaneSolvent

Procedure

4.18 kg (35.4 mol) of 1-fluoro-2,2-dimethyl-butan-3-one were dissolved in 30 liters of methylene chloride, and 5.67 kg of bromine were added dropwise at 20° C. in the course of 2 hours such that continuous decolorisation occurred. The solvent was distilled off under a waterpump vacuum, a further 15 liters of methylene chloride were added to the residue and the solvent was again distilled off under a waterpump vacuum. The crude 1-fluoro-4-bromo-2,2-dimethyl-butan-3-one (6.97 kg, quantitative yield) was added dropwise to 2.45 kg of 1,2,4-triazole and 4.89 kg of potassium carbonate in 21.4 liters of acetone at 30° to 35° C. in the course of 2 hours, whilst cooling. The mixture was subsequently stirred at room temperature for 15 hours, the insoluble material was filtered off and the solvent was distilled off from the filtrate under a waterpump vacuum. 6.12 kg (93% of theory) of 1-fluoro-2,2-dimethyl-4-(1,2,4-triazol-1-yl)-butan-3-one, which could be further reacted directly, were obtained.

Workup

  1. distillationThe solvent was distilled off under a waterpump vacuum
  2. additiona further 15 liters of methylene chloride were added to the residue
  3. distillationthe solvent was again distilled off under a waterpump vacuum

Sources & evidence

ORD record
ord-6428753491dc4ed2a8f98ccfea05e1ca
Source dataset
uspto-grants-1987_12
Patent number
US04711657

Reaction notes

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