Preparation of thioketones, mercaptals, and mercaptols

The halogen atoms of the geminal dihalo derivatives of diaryl diketones and of heterocyclic ketones can be replaced in reactions with sulfur compounds 0e.g., sodium hydrogen sulfide, thioacetic acid, phosphorus pentasulfide), thioketones being formed.318,319 Staudinger and Freudenberger,320 for instance, obtained thiobenzophenone in 46% yield from benzophenone dichloride (dichlorophenylmethane) and a hot alcoholic solution of sodium hydrogen sulfide  

In a generally applicable reaction numerous derivatives of the thiobenzophenone series have been obtained by the action of thioacetic acid on aromatic ketone dichlorides 321 

10-Thioxanthone322 (5.7 g) is boiled with oxalyl chloride, with exclusion of moisture, for 20 h on a water-bath, and the mixture a is then evaporated to dryness in a vacuum at 100°. The residue is dissolved in dry benzene (75 ml) and treated with thioacetic acid (10 g) in 

As additional method of preparing thioketones the reaction of aromatic compounds with thiophosgene under Friedel-Crafts conditions deserves mention.323,324 

Further, thiopyridones and quinaldinethiones can be obtained by the action of alkali hydrogen sulfides on halopyridinium and haloquinaldinium salts 325 326 

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