Hydrochloric Acid → 1-Benzyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine

HRID 977955Notes

Reaction equation

HRID 977955 reaction equation
[CH2:1]([N:8]1[C:13](=[O:14])[C:12](=[C:15]2[S:19][CH:18]=[CH:17][S:16]2)[C:11](=[O:20])[CH:10](C(OCC)=O)[CH2:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[Na+].Cl>C(O)C>[CH2:1]([N:8]1[CH2:9][CH2:10][C:11](=[O:20])[C:12](=[C:15]2[S:16][CH:17]=[CH:18][S:19]2)[C:13]1=[O:14])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 13934862Ethyl 1-benzyl-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-3-carboxylate

Product 1

HCID 136065591-Benzyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidineYield 78%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl 1-benzyl-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-3-carboxylate (2.0 g) is dissolved in ethanol (160 ml), and a 10% aqueous sodium hydroxide solution (8.0 ml) is added thereto. The mixture is refluxed for 2 hours. The mixture is cooled, neutralized with 10% hydrochloric acid, and then evaporated under reduced pressure to remove the solvent. The residue is dissolved in ethyl acetate, and the solution is washed with water, dried and then evaporated to remove the solvent. The residue thus obtained is recrystallized from isopropanol, whereby 1-benzyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine (1.26 g) is obtained as pale yellow needles. Yield: 78%.

Workup

  1. temperatureThe mixture is refluxed for 2 hours
  2. temperatureThe mixture is cooled
  3. customevaporated under reduced pressure
  4. customto remove the solvent
  5. dissolutionThe residue is dissolved in ethyl acetate
  6. washthe solution is washed with water
  7. customdried
  8. customevaporated
  9. customto remove the solvent
  10. customThe residue thus obtained
  11. customis recrystallized from isopropanol

Sources & evidence

ORD record
ord-37a9a66402b8473f8bd98f6f8567048c
Source dataset
uspto-grants-1987_05
Patent number
US04663319

Reaction notes

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