Carbon Disulfide → 1-Benzyl-3-(1,3-dithiol-2-ylidene)-2,4-dioxopiperidine

Participants

Reaction Steps

Sodium hydride (60% despersion in oil) (432 mg) is suspended in dimethylsulfoxide (10 ml), and to the suspension is added dropwise a solution of 1-benzyl-2,4-dioxopiperidine (1.0 g) and carbon disulfide (0.33 ml) in dimethylsulfoxide (20 ml). The mixture is stirred for 2 hours, and thereto is added dropwise a solution of cis-1,2-dichloroethylene (0.42 ml) in dimethylsulfoxide (5 ml). The mixture is stirred at room temperature for 1.5 hour and further at 50° C. for 1 hour. The reaction mixture is poured onto water and extracted with benzene. The extract is washed with water, dried and then distilled to remove the solvent. The residue is recrystallized from isopropyl alcohol to give 1-benzyl-3-(1,3-dithiol-2-ylidene)-2,4- dioxopiperidine (486 mg) as pale yellow needles. m.p. 122°-124° C.

Provenance & Evidence