1-Ethylpiperidine-2,4-dione → 1-Ethyl-3-methoxymethylenepiperidine-2,4-dione

HRID 569990Notes

Reaction equation

HRID 569990 reaction equation
[CH2:1]([N:3]1[CH2:8][CH2:7][C:6](=[O:9])[CH2:5][C:4]1=[O:10])[CH3:2].[CH:11]([O-])([O-])[O:12][CH3:13]>C(OC(=O)C)(=O)C>[CH2:1]([N:3]1[CH2:8][CH2:7][C:6](=[O:9])[C:5](=[CH:11][O:12][CH3:13])[C:4]1=[O:10])[CH3:2]

Participants

4

Reactant 2

HCID 137841191-Ethylpiperidine-2,4-dioneHCID 53629101Methylorthoformate

Product 1

HCID 540921521-Ethyl-3-methoxymethylenepiperidine-2,4-dioneYield 25.1%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

Added to 8.3 g of 1-ethylpiperidine-2,4-dione were 11 g of methyl orthoformate and 20 ml of acetic anhydride. The resultant mixture was refluxed for 7 hours. After allowing the reaction mixture to cool down, excess methyl orthoformate and acetic anydride were distilled off under reduced pressure. The brown residue was distilled under reduced pressure in a Kugelroll apparatus (0.5 mmHg; bath temperature: 200°-250° C.) to obtain 2.7 g of 1-ethyl-3-methoxymethylenepiperidine-2,4-dione as crystals (yield: 25%). The crystals were recrystallized from a mixed solvent of ethyl acetate and hexane to obtain needles.

Workup

  1. temperatureto cool down
  2. distillationexcess methyl orthoformate and acetic anydride were distilled off under reduced pressure
  3. distillationThe brown residue was distilled under reduced pressure in a Kugelroll apparatus (0.5 mmHg; bath temperature: 200°-250° C.)

Sources & evidence

ORD record
ord-31eebf9e4afb46a98abce0f961ffe098
Source dataset
uspto-grants-1988_03
Patent number
US04734418

Reaction notes

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