CXXVII.—The preparation of guanidine by the interaction of dicyanodiamide and ammonium thiocyanate

Abstract

CXXVIL-The Preparation of Gua.nidine by the Interaction of Dicyanodiarnide and Ammonium Thioc yanat e. By EMIL ALPHONSE WERNER and JAMES BELL. BY heating a mixture of dicyaaodiamide and ammonium chloride a t 195O folr ten minutes, Bamberger and Dieckmann (Ber., 1892, 25, 545) obtained diguanidei, C,H,N,. The yieild wa,s pooh, and Ostrogovich (Bul. Soc. qtainfe Bucaregti 1910, 19, 641), using ammonium iodidei in plaae oif the ohloride, under similar wnditiolns, obtained it much btter resulti. The reactioin has been represented thus: HN:c(NH,)*NH.CN + NR,*HX= * This fact is not referred to in the literature : if a gram or two of dioyanodiamide i8 heated to the melting point in a porcelain crucible and quickly covered with a glass bell-jar standing over a layer of water, the latter after a few momentswill be found t o give quite a copious yellow precipitate of silver cytmamide on addition of ammonio-silver nitrate solution. u u'

Synthesis and Insecticidal Properties of Some Cholinergic Trisubstituted Acetaldehyde O-(Methylcarbamoyl)oximes

“…5. S. [9][10][11][12][13][14][15][16][17][18][19][20][21]. Captan [(A'-trichloromethylthio)-4-cvclohexene-1.2-dicarboximide.…”

Quantitative Study of the Preparations of Guanidine Nitrate and Nitroguanidine

“…Thiele (24) and Volhardt (26) prepared guanidine thiocyanate by heating ammonium thiocyanate. In 1920 Werner and Bell (28) prepared guanidine thiocyanate by fusing ammonium thiocyanate and dicyandiamide, but this method recalls earlier work in which is recorded the formation of guanidine salts (21), as well as biguanide salts (1,22), by the action of ammonium salts on dicyandiamide. In addition, guanidine has been obtained from cyanamide and ammonium salts (12), ammonia and phosgene (5), and the treatment of orthocarbonic esters with ammonia (17).…”

“…obtained fair yields of the respective guanidine salt. Their work does not reveal the optimum conditions, and in explaining the mechanism of the reaction they assumed, as did Werner and Bell (28), the depolymerization of dicyandiamide to cyanamide and the subsequent ammoniation of cyanamide to guanidine. Davis (8,29) and Blair and Braham (4) working independently isolated an intermediate compound, the biguanide salt, and formulated a mechanism of the reaction by which cyanoguanidine is first ammoniated to biguanide and the latter in turn ammoniated to guanidine.…”

“…The work of Werner and Bell (28) suggested to other investigators who worked independently the feasibility of obtaining other salts of guanidine directly from the respective ammonium salt and dicyandiamide. This was advisable because the Werner and Bell reaction yields a product which is difficult to purify owing to the presence of thio compounds and to the deliquescence of guanidine thiocyanate.…”

Metformin - A Panacea Pharmaceutical Agent through convergence revolution initiative

“…Equimolar quantities of dimethylamine and 2-cyanoguanidine are made into a solution using toluene as the solvent, with gradual addition equimolar amount of hydrogen chloride the solution starts boiling and upon cooling, precipitation occurs. The precipitate formed is N, N-dimethylimidodicarbonimidic diamide hydrochloride with a 96% yield which is Metformin hydrochloride 2,3 . Metformin hydrochloride (IUPAC: N, N-dimethylimidodicarbonimidic diamide hydrochloride) is the Active Pharmaceutical Ingredient (API) of the finished product of the oral antihyperglycemic drug used for the treatment and management of type 2-diabetes.…”