Synthesis of Thioacyl Halides

It has been emphasized by Kato and his co-workers that di- and tri-alkyl-ammonium dithiocarboxylates are readily obtained as stable crystals, which are more useful than metal salts in the purification and preparation of derivatives. Synthesis of Thioacyl Halides.—Aromatic thioacyl chlorides, but not the unknown thioacetyl chloride, have been prepared in a convenient way, using phosgene as the chlorinating agent.  

Aliphatic thioacyl chlorides, e.g. Bu CH2C(S)Cl and Bu CHClC(S)Cl, can be obtained by addition of hydrogen chloride or chlorine, respectively, to the thioketen Bu CH=C=S, generated by flash pyrolysis of 4-t-butyl-l,2,3-thiadi-azoles or by direct reaction with the heated thiadiazole. The addition of hydrogen chloride to the alkynethiolate ion Bu C=CS also gives the thioacyl chloride Bu CHaC(S)Cl. Addition of thiophosgene to the enamine Mc2NC(Bu )=CHa 

When trifluoroiodoethylene was bubbled through boiling sulphur, tetra-fluorodithiosuccinyl difluoride, FC(S)(CF2)2C(S)F, was formed.  

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