Method for preparing 5-mercapto-1,2,3-thiadiazole salts

A method for preparing a 5-mercapto-1,2,3-thiadiazole salt represented by the general formula (I):

• ##STR17## comprising the steps of:
• providing a sulfonylhydrazone derivative represented by the general formula (II):
• ##STR18## providing a sulfide represented by the general formula (III):
• M--S--M' (III)
• (wherein R is an aryl group, X is a chlorine or bromine atom, M is an alkali metal atom and M' is a hydrogen atom or an alkali metal atom);
• combining the sulfonylhydrazone derivative represented by the general formula (II) and the sulfide represented by the general formula (III) and allowing a reaction to occur;
• and
• obtaining the 5-mercapto-1,2,3-thiadiazole salt represented by the general formula (I) wherein the sulfide represented by the general formula (III) is present in an amount of not less than 3 molar equivalents based on the amount of the sulfonylhydrazone derivative represented by the general formula (II).