Toluene → 2,3,5-Trimethylpyridine

HRID 979850Notes

Reaction equation

HRID 979850 reaction equation
C[Li].[N:3]1[CH:8]=[C:7]([CH3:9])[CH:6]=[C:5]([CH3:10])[CH:4]=1.[C:11]1(C)C=CC=CC=1>CCOCC>[N:3]1[CH:8]=[C:7]([CH3:9])[CH:6]=[C:5]([CH3:10])[C:4]=1[CH3:11]

Participants

5

Reactant 3

HCID 1140TolueneHCID 115653,5-DimethylpyridineHCID 178418348HCID 178418348, compound

Product 1

HCID 127592,3,5-Trimethylpyridine

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

To 500 ml of a 5% solution of methyl lithium in ether were added dropwise at room temperature under argon 1200 ml of ether, subsequently 35.6 g of 3,5-lutidine (3,5-dimethylpyridine) and finally 400 ml of toluene. The ether was distilled off completely, whereupon the solution was stirred at 100° for 4 hours. Ice was then added portionwise thereto while cooling with methanol/ice until the evolution of heat no longer occurred. The toluene phase was separated from the precipitated solid and was extracted with 66 ml of semi-concentrated hydrochloric acid. The separated aqueous phase was adjusted to a pH of about 10 with 3N sodium hydroxide solution while cooling and extracted twice with 300 ml of ether. The ether extracts were dried over sodium sulfate and evaporated. The residue was distilled in vacuo at 20 mm/72°-74°; there was obtained 2,3,5-collidine (2,3,5-trimethylpyridine) which had a 99.15% purity in accordance with gas chromatography.

Workup

  1. distillationThe ether was distilled off completely
  2. additionIce was then added portionwise
  3. temperaturewhile cooling with methanol/ice until the evolution
  4. temperatureof heat no longer
  5. customThe toluene phase was separated from the precipitated solid
  6. extractionwas extracted with 66 ml of semi-concentrated hydrochloric acid
  7. temperaturewhile cooling
  8. extractionextracted twice with 300 ml of ether
  9. dry with materialThe ether extracts were dried over sodium sulfate
  10. customevaporated
  11. distillationThe residue was distilled in vacuo at 20 mm/72°-74°

Sources & evidence

ORD record
ord-1ce37b5cd865420ba27ce326cd241523
Source dataset
uspto-grants-1987_01
Patent number
US04634710

Reaction notes

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