[Determination of thiocarbamide and related derivatives using an S-alkylation reaction]

S-alkylation reaction based on the Hantzsch synthesis followed by cyclization and aromatization reactions were used to develop an analytical procedure. The various thiocarbamide derivatives were transformed to substituted aminothiazol by using suitable alpha-halogenoketones as the reagents. At the end of the reaction the reaction products are present as 2-aminothiazol salts. The acidimetric determination of the latter can easily be performed using acetone or methanol as the solvents and 0.1 M sodium hydroxide as the titrant. The forming 2-aminothizols with their different basicities are characteristic of the parent thiocarbamide derivatives. On the basis of the different basicities their simultaneous determination is possible and the shape of the titration curves enables the thiocarbamides to be characterized and identified.