2,4-Dichloro-3,5,6-trimethylpyridine → 4-Chloro-2,3,5-trimethylpyridine

HRID 2231950Notes

Reaction equation

HRID 2231950 reaction equation
[Cl:1][C:2]1[C:7]([CH3:8])=[C:6](Cl)[N:5]=[C:4]([CH3:10])[C:3]=1[CH3:11].[H][H]>C(O)C.S(=O)(=O)(O)O.[Pd]>[Cl:1][C:2]1[C:7]([CH3:8])=[CH:6][N:5]=[C:4]([CH3:10])[C:3]=1[CH3:11]

Participants

6

Reactant 2

HCID 27791392,4-Dichloro-3,5,6-trimethylpyridineHCID 178418361HCID 178418361, compound2×

Product 1

HCID 142036064-Chloro-2,3,5-trimethylpyridineYield 78%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 1118Sulfuric AcidSolvent

Procedure

200 g 4,6-dichloro-2,3,5-trimethylpyridine dissolved in 300 ml ethanol and 40 ml conc. sulphuric acid. 2 g 10% Pd/C was used as catalyst. The hydrogen pressure was 2 bar and the hydrogenation was stopped when 1 equivalent of hydrogen had been consumed. After evaporation of alcohol and dilution with water and adjustment of pH to 2.1 the water was extracted with toluene. The toluene contains all starting material and 6-chloro-2,3,5-trimethylpyridine and the water phase 4-chloro-2,3,5-trimethylpyridine and 2,3,5-trimethylpyridine. The pH of the water phase is adjusted to 4.6 and extracted with toluene (3x100 ml). All 4-chloro-2,3,5-trimethylpyridine is in the toluene layer and the 2,3,5-trimethylpyridine in the water. Evaporation of the toluene gave 4-chloro-2,3,5-trimethylpyridine in 78% yield (liquid). NMR: 2×3H, 2,3; 3H, 2,5(s); 1H, 8,25(s). (CDCl3)

Workup

  1. customhad been consumed
  2. customAfter evaporation of alcohol and dilution with water and adjustment
  3. extractionwas extracted with toluene
  4. extractionextracted with toluene (3x100 ml)
  5. customEvaporation of the toluene

Sources & evidence

ORD record
ord-f3ebc192681442b0aab57f9285dc4b81
Source dataset
uspto-grants-1988_11
Patent number
US04785113

Reaction notes

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