The reaction of 2-furan-methanol (I) with dimethylamine and formaldehyde gives 5-(dimethylaminomethyl)furan-2-methanol (II), which is condensed with 2-sulfanylethylamine (III) yielding 2-[5-(dimethylaminomethyl)furan-2-ylsulfanyl]ethylamine (IV). The condensation of (IV) with 1-(methylamino)-1-(methylsulfanyl)-2-nitroethylene (V), obtained from 1,1,-bis(methylsulfanyl)-2-nitroethylene (VI) and methylamine, in hot acetone, or by heating at 100-120 C affords N-[2-[5-(dimethylaminomethyl)furan-2-ylmethylsulfanyl]ethyl]- N'-methyl-2-nitroethylene-1,1-diamine (VII) , which is finally complexed with bismuth (+3) citrate (VIII), obtained by reaction of NO3BiO with citric acid (IX) in hot water.