The invention provides a process for preparing a 4-amino-5-mercapto-3-substituted-\x9b1,2,4!triazole comprising reacting a thiocarbohydrazide with a carboxylic acid in the presence of an organic solvent and a boron compound having the formula ##STR1## where R.sup.2, R.sup.3, and R.sup.4 are independently selected from the group consisting of hydrogen, hydroxy, amino, alkyl, aryl, alkoxy, and aryloxy groups. The process provides a safer low temperature process for preparing the desired compound.