| 摘要 |
The invention comprises thioesters of cyanoimidoformic acid having the formula NC-C(:NH)-SR where R is an organic radical, e.g. an alkyl, alkenyl, aryl, aralkyl or heterocyclic group. The compounds can be made by the reaction of a mercaptan, RSH, with excess dicyanogen, preferably in the presence of a catalyst which contains mercaptide ions or which reacts with RSH to give mercaptide ions or a catalyst which is an amine or quaternary ammonium compound. Numerous catalysts are specified. In the case of the catalyst being a compound of magnesium, aluminium or a heavy metal, the dicyanogen need not be used in excess of the mercaptan. With other catalysts, excess mercaptan results in the formation of di-imidooxalic acid dithioesters. The reaction may be effected at temperatures in the range -30 DEG to 150 DEG C. and in the presence of an inert solvent or in the gas phase. Numerous examples are provided. |
