The Mannich reaction of tricyclo[2.2. 1.0(2,6)]hept-3-ylamine hydrochloride (I) with 2-furanylmethanol (II) and paraformaldehyde (III) in ethanol gives 5-(tricyclo[2.2. 1.0(2,6)]hept-3-ylamino)methyl-2-furanyl methanol (IV). The reaction of compound (IV) with 2 mercaptoethylamine (V) by means of concentrated HCl affords 2 [[[5-[(tricyclo[2.2.1.0(2,6)]hept-3-yl-amino(methyl]-2-furanyl]methyl]thio]etheneamine (VI), which is converted with 1 1-bis(methylthio)-2-nitroethene (VII) in isopropyl alcohol by heating at 70 C to N-[2-[[[5 [(tricyclo[2.2.1.O(2,6)]hept-3-ylamino)methyl]-2-furanyl]methyl]thio]ethyl]-1-(methylthio)-2-nitroetheneamine (VIII). Compound (VIII) is then treated with excess methylamine in ethanol at 0 C, followed by treatment with ethereal HCl to give the desired-N-[2-[[[5 [(tricyclo[2.2. 1.0(2,6)]hept-3-ylamino)methyl]-2 furanyl]methyl]thio]ethyl] N'- methyl-2-nitro-1,1-ethenediaminehydrochloride.