Methyl iodide → 1-Methyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine

HRID 977946Notes

Reaction equation

HRID 977946 reaction equation
[H-].[Na+].[S:3]1[CH:7]=[CH:6][S:5][C:4]1=[C:8]1[C:13](=[O:14])[CH2:12][CH2:11][NH:10][C:9]1=[O:15].[CH3:16]I>CN(C)C=O>[CH3:16][N:10]1[CH2:11][CH2:12][C:13](=[O:14])[C:8](=[C:4]2[S:5][CH:6]=[CH:7][S:3]2)[C:9]1=[O:15]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 136065623-(1,3-Dithiol-2-ylidene)-2,4-dioxopiperidine

Product 1

HCID 136065631-Methyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidineYield 59.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

Sodium hydride (60% dispersion in oil) (226 mg) is suspended in N,N-dimethylformamide (10 ml), and to the suspension is added dropwise a solution of 3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine (1.0 g) (which is prepared in Example 13) in N,N-dimethylformamide (100 ml) while cooling at 0° to 5° C. The mixture is stirred for 10 minutes at the same temperature, and to the mixture is added dropwise methyl iodide (861 mg), and the mixture is stirred at 0° to 2° C. for 1.5 hour. After distilling off the solvent under reduced pressure, the residue is purified by silica gel column chromatography (solvent, n-hexane:ethyl acetate=1:1), and recrystallized from ethyl acetate-isopropyl ether to give 1-methyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine (634 mg, 59.5%) as pale yellow needles. m.p. 148.5°-153° C.

Workup

  1. temperaturewhile cooling at 0° to 5° C
  2. stirringthe mixture is stirred at 0° to 2° C. for 1.5 hour
  3. distillationAfter distilling off the solvent under reduced pressure
  4. customthe residue is purified by silica gel column chromatography (solvent, n-hexane:ethyl acetate=1:1)
  5. customrecrystallized from ethyl acetate-isopropyl ether

Sources & evidence

ORD record
ord-5d3bcf8875ab4c29afdd69d1423c9708
Source dataset
uspto-grants-1987_05
Patent number
US04663319

Reaction notes

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