Sodium Sulfide → Methyl 4,6-dihydrothieno[3,4-b]thiophene-2-carboxylate

HRID 572903Notes

Reaction equation

HRID 572903 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([CH2:12]Cl)=[C:8]([CH2:10]Cl)[CH:9]=1)=[O:4].[S-2:14].[Na+].[Na+]>CO>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]2[CH2:12][S:14][CH2:10][C:8]=2[CH:9]=1)=[O:4]

Participants

4

Reactant 2

HCID 14804Sodium SulfideHCID 11096691Methyl 4,5-bis(chloromethyl)thiophene-2-carboxylate

Product 1

HCID 3441857Methyl 4,6-dihydrothieno[3,4-b]thiophene-2-carboxylateYield 50%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

A solution of 4.8 g (20 mmol) (2) in 240 mL methanol was heated up and kept mild boiling. Sodium sulfide solution (1.7 g, 22 mmol) in 160 mL methanol was added dropwise in 2 h. After cooling of the reaction mixture, the precipitate was filtered off. The solvent was removed by evaporation and the residue was washed by water. Column chromatography on silica gel using dichloromethane yielded the pure title compound as a white solid 2.0 g (50%). 1HNMR (CDCl3): δ 3.87 (3H, s), 4.05-4.06 (2H, t, J=3 Hz), 4.19-4.20 (2H, t, J=3 Hz), 7.48 (1H, s). 13CNMR (CDCl3): 633.12, 33.47, 52.19, 127.90, 137.30, 143.90, 146.64, 162.51.

Workup

  1. temperatureAfter cooling of the reaction mixture
  2. filtrationthe precipitate was filtered off
  3. customThe solvent was removed by evaporation
  4. washthe residue was washed by water

Sources & evidence

ORD record
ord-8c7201cd653942c1ae5894293f6aa9ec
Source dataset
uspto-grants-2015_05
Patent number
US09029499B2

Reaction notes

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