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

HRID 1252281Notes

Reaction equation

HRID 1252281 reaction equation
[CH:1]([O-])([O-])[O:2][CH3:3].[CH2:6]([N:8]1[CH2:13][CH2:12][C:11](=[O:14])[CH2:10][C:9]1=[O:15])[CH3:7]>C(OC(=O)C)(=O)C>[CH2:6]([N:8]1[CH2:13][CH2:12][C:11](=[O:14])[C:10](=[CH:1][O:2][CH3:3])[C:9]1=[O:15])[CH3:7]

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

11 g of methyl orthoformate and 20 ml of acetic anhydride were added to 8.3 g of 1-ethylpiperidine-2,4-dione, and they were refluxed for 7 hours and then allowed to cool. Excessive methyl orthoformate and acetic anhydride were removed by vacuum distillation. The resulting brown reside was subjected to vacuum distillation (0.5 mmHg, bath temperature of 200° to 250° C.) using a kugelrohr apparatus, whereby 2.7 g of 1-ethyl-3-methoxymethylenepiperidine-2,4-dione was obtained as a crystal with an yield of 25%. This crystal was recrystallized from a mixed solvent consisting of ethyl acetate and hexane to obtain a needle-like crystal of said compound.

Workup

  1. temperaturewere refluxed for 7 hours
  2. temperatureto cool
  3. customExcessive methyl orthoformate and acetic anhydride were removed by vacuum distillation
  4. distillationThe resulting brown reside was subjected to vacuum distillation (0.5 mmHg, bath temperature of 200° to 250° C.)

Sources & evidence

ORD record
ord-6a5d9c2d500a41b58385f101938adeca
Source dataset
uspto-grants-1988_05
Patent number
US04742165

Reaction notes

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