Reaction #362038

Reaction equation

dithiolate

1-cyanomethylimidazole

carbon disulfide

hydroxide

1,2-dibromo-1-(4-t-butoxyphenyl)ethane

→

2-(1-Imidazolyl)-2-{4-(hydroxyphenyl)-1,3-dithiolane-2-ylidene}acetonitrile

Yield 16.8%

Solvents

dimethyl sulfoxide

dimethyl sulfoxide

Conditions

Workup

1. 1
   workup.STIRRINGby stirring for 2 hours
2. 2
   workup.ADDITIONTo the reaction mixture was added 200 ml of icewater
3. 3
   Extractionthe mixture was extracted with ethyl acetate
4. 4
   WashThe organic layer was washed with water
5. 5
   Dryingdried over magnesium sulfate
6. 6
   Concentrationconcentrated
7. 7
   Otherto obtain
8. 8
   workup.ADDITIONa mixture of geometric isomers as a viscous oily substance
9. 9
   OtherPurification of the product by silica gel chromatography
10. 10
    Othergave 2.4 g (yield: 16.8%) of a Z-isomer and 4.5 g (yield: 31.5%) of an E-isomer

Procedure

In 40 ml of dimethyl sulfoxide were dissolved 4.6 g (0.004 mol) of 1-cyanomethylimidazole, 3.1 g (0.005 mol) of carbon disulfide and 5.2 g of pottassium hydroxide powder by stirring at room temperature for 1 hour to prepare a dithiolate solution. The solution was added dropwise to a solution of 14.8 g (0.04 mol) of 1,2-dibromo-1-(4-t-butoxyphenyl)ethane in 40 ml of dimethyl sulfoxide at 30° C., followed by stirring for 2 hours. To the reaction mixture was added 200 ml of icewater, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dried over magnesium sulfate, and concentrated to obtain a mixture of geometric isomers as a viscous oily substance. Purification of the product by silica gel chromatography gave 2.4 g (yield: 16.8%) of a Z-isomer and 4.5 g (yield: 31.5%) of an E-isomer both as a viscous oily substance.

Source