Reaction #69883

Reaction equation

4,5-bis(bromomethyl)-1,3-dithiol-2-thione

p-benzoquinone

dichloro dicyano benzoquinone

→

2-thioxonaphth[2,3-d] [1,3]dithiol-5,8-dione

Yield 78.0%

Solvents

acetonitrile

Conditions

Workup

1. 1
   Temperaturerefluxed for 1 hour
2. 2
   Temperaturerefluxed for 7 hours
3. 3
   workup.DISTILLATIONAfter completion of the reflux, the solvent was distilled away
4. 4
   workup.ADDITIONmethanol was added in the vessel
5. 5
   Filtrationthe precipitate was recovered through filtration
6. 6
   WashThe precipitate was washed with methanol
7. 7
   workup.DISTILLATIONdistilled water, and ether in this order
8. 8
   workup.DISSOLUTIONthe obtained residue was dissolved in chloroform
9. 9
   Filtrationfiltered
10. 10
    OtherThe obtained filtrate was recrystallized

Procedure

In a vessel, the 4,5-bis(bromomethyl)-1,3-dithiol-2-thione: 1-3 (1.10 g), tetraethylammonium iodide (0.38 g), p-benzoquinone (2.77 g), and acetonitrile (60 mL) were charged, and then refluxed for 1 hour. Thereafter, dichloro dicyano benzoquinone (1.62 g) was added in the resultant mixture, and then refluxed for 7 hours. After completion of the reflux, the solvent was distilled away, and methanol was added in the vessel, and then the precipitate was recovered through filtration. The precipitate was washed with methanol, distilled water, and ether in this order, the obtained residue was dissolved in chloroform, and then filtered. The obtained filtrate was recrystallized, to thereby obtain 2-thioxonaphth[2,3-d] [1,3]dithiol-5,8-dione: 1-4 in a yield of 78%. The target compound was identified through NMR analysis: 1H-NMR (CDCl3, TMS) σ: 7.04 (s, 2H), 8.15 (s, 2H).

Source