Trithiocarbonic acid, alkyl esters

Carbon disulfide is a valuable synthon (see Chapter 9, p. 147) which can be used for the synthesis of thiocarbonic acid derivatives. Thus, carbon disulfide reacts with ammonium polysulfide or hydrogen sulfide to give trithiocarbonic acid (70) or symmetrical esters (73) after reaction with an alkyl halide. With alkoxides or thiolates, carbon disulfide forms xanthates (77) or S-alkyl trithiocarbonates the latter by further treatment with alkyl, acyl or diazonium halides affords the derivatives (74)-(76) (Scheme 39). 

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