To a solution of 22.7 g of quinone monoguanylhydrazone nitrate in 250 ml
water is added dropwise hot aqueous solution of 9.1 g thiosemicarbazide, then
is added slowly a solution of 5 ml concentrated nitric acid in 10 ml of water.
The mixture is stirred at 60°C for 1 hour. The product is dissolved in 1-1.2 L
of water at 100°C. The solution is filtered and added to an aqueous
ammonium solution. Blue residue of p-benzoquinone amidinohydrazone
thiosemicarbazone is filtered and dried, melting point 188°C (decomp.).
