In an RBF, 5.7 mL of ethyl cyanoacetate and 5.2 mL of cyclohexanone are dissolved in 15 mL of anhydrous ethanol by magnetic stirring. To this solution, 1.6 g of sulfur is added, after which a slow addition of 4 mL of morpholine over a few minutes is started over stirring. Then the RBF is capped and the mixture is stirred for 2 h after the stirring is completed the solution will be completely crystallized. The stirring is stopped and the mixture is let to stay at room temperature for 2 h. The mixture is then broken down, washed with a little bit of cold ethanol and filtered. The crude product is recrystallized with hot ethanol.
The solution before the additions
The solution after the additions
Agitation of the solution
The solution crystallized
The crude product
The recrystallized product