Thionyl Chloride → 9-Oxo-9H-thioxanthene-3-carbonitrile 10,10-dioxide

Participants

Reaction Conditions

Reaction Steps

3-Carbamoylthioxanthone-10,10-dioxide (32.5 g) was dissolved in dimethyl formamide (ca. 1 litre) and cooled to -10° C in a solid carbon dioxide ethanol bath. Thionyl chloride (80 ml) was then added dropwise over 0.5 hour, maintaining the internal temperature at -5° to -10° C. Stirring was continued at this temperature for a further 2 hours. The reaction mixture was then poured into ice-water. The precipitated solid was filtered off, washed well with water, and dried at 100° C. The resulting 3-cyanothioxanthone-10,10-dioxide had a melting point of 282- 283° C.

Provenance & Evidence