From Cyanamides

Alkylation of monotritylcyanamide 92 with trityl chloride affords bis(trityl)carbodiimide 

With less sterically hindered substituents, mixtures of carbodiimides and disubstituted cyanamides are obtained. 

Carbodiimide 95 is also prepared from cyanamide and the olefin 94 with t-buty 1 hypochlorite, possibly through a free radical process.  

Photolysis of t-buty 1-N-chlorocyanamide 96 in the presence of cyclohexene gives a 22% yield of carbodiimide 97.  

Numerous metal substituted carbodiimides are synthesized from cyanamides (see Sections 1.5 and 1.9) 

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The advantage of this method is that it avoids the use of hydrogen selenide, necessary for the preparation of selenourea from cyanamide (14). Benzoylselenourea is synthesized by the method of Douglass (24) by the action of potassium selenocyanate On benzoyl chloride in acetone solution. 

DiaminO 4,4-dimethyl-l,3,5-thiadiazine hydrobromide was isolated as by-product (418). Benzene sulfonates of cyanohydrin prepared from sodium cyanide and an halobenzoaldehyde, when treated with thiourea or its derivatives, afford 2,4-diamino-5-(p-halogenophenyl)-thiazole benzene sulfonates (447). Similarly, cyanoamido thiocarbamates obtained from cyanamide and isothiocyanates yield substituted 2,4-diaminothiazoles (598). 

Amino resins are condensation thermosetting polymers of formaldehyde with either urea or melamine. Melamine is a condensation product of three urea molecules. It is also prepared from cyanamide at high pressures and temperatures ... 

At the same time a small amount of hydrogen sulphide is also eliminated. The main product of this reaction, carbodiphenylimide (di-phenylcyanamide), an extremely reactive substance, combines with the aniline present in the solution to form triphenylguanidine in the same way as, from cyanamide itself and ammonia, the unsubstituted guanidine is formed. 

The new phosphazene triazene hybrid ring compound (42) can be obtained from cyanamide by two slightly different routes, A96 and B97 (Scheme 11). Substitution of ammonia in route B leads to further ring compounds (43) and (44a, b).97... 

Odo studied the formation of methylguanidine from cyanamide and aqueous mixtures of methylamine and methylamine hydrochloride in various proportions [ 110]. He concluded that the reaction occurred by a reversible nucleophilic attack of the free amine on cyanamide, and that an acid was required to shift the equilibrium in the direction of the guanidine. 

Schulze and Winterstein, in 1899, proved that aiginine was S-guani-dine-a-aminovalerianic acid by s)mthesis from cyanamide and ornithine —... 

Changing the nature of the triazine substitution pattern to the l,3,5-triazine-2,4-dione system leads to another series of herbicides, of which the best example is hexazinone (1) (75USP3902887). It is built up from cyanamide which is converted in several steps to the guanidine (2). Reaction with cyclohexyl isocyanate then gives an intermediate which can be cyclized to hexazinone (Scheme 2). 

The halonitro compounds and the methanol used were of purum or pract. quality from Fluka. The amidine derivatives (in the form of their salts) were purchased from Fluka or Aldrich (purum or pract.). The N,N-dialkyl-formamidine acetates were prepared by analogy to a published procedure (ref. 8) from cyanamide and used as isolated (containing ca. 10% ammonium acetate). 

The nitroamines are substituted ammonias, substances in which a nitro group is attached directly to a trivalent nitrogen atom. They are prepared in general either by the nitration of a nitrogen base or of one of its salts, or they are prepared by the splitting off of water from the nitrate of the base by the action of concentrated sulfuric acid upon it. At present two nitroamines are of particular interest to the explosives worker, namely, nitro-guanidine and cyclotrimethylenetrinitramine (cyclonite). Both are produced from synthetic materials which have become available in large commercial quantities only since the first World War, the first from cyanamide, the second from formaldehyde from the oxidation of synthetic methyl alcohol. 

Large quantities of guanidine are made from cyanamide. Two methods are available for this... 

In an initial step, 2-chloroacetic acid ethyl ester is reacted with formamide to give 5-methylimidazole-4-carboxylic acid ethyl ester. Then sodium in ammonia is used to convert that to 4-hydroxymethyl-5-methylimidazole-hydrochloride. Cysteamine HCI (HSCH2CH2NH2-HCI) is then reacted to give 4-(2-aminomethyl)-thiomethyl-5-methyl-imidazole dihydrochloride. Then N-cyanamido-5,5-dimethyl-dithio-carbonate (from cyanamid, KOH, CS2 and ((CH3)2S04) is reacted to give a further intermediate which is finally reacted with methylamine to give cimetidine. 

As an extension of the known radical additions to isonitriles [87], aryl radical cyclizations to /V-acyl cyanamides provide new access to pyrrolo-quinazolines (Scheme 16) [88]. In a tandem process, the iminyl radical 41 resulting from the 5-exo cyclization onto the nitrile was used for a second cyclization step. In this way, the alkaloid luotonin A (42) was synthesized from cyanamide 43 in a single reaction. 

Cyanodithioimidocarbonate salts have become very useful reagents for the preparation of many 3,5-disubstituted 1,2,4-thiadiazoles. Dipotassium cyanodithioimidocarbonate (314) is readily prepared from cyanamide and carbon disulfide under alkaline conditions and is readily converted into the reactive thiadiazoles (315), (316), (317), (318) and (319), as shown in Scheme 112 (71JOC14). Alkylation of (314) produces derivatives of type (320) which react with chlorine or sulfuryl chloride to yield 5-alkylthio-3-chloro-l,2,4-thiadiazoles... 

X = Cl) (67JOC1566). The alkyl cyanodithioimidocarbonates (320) and the oxygen and nitrogen analogs (322 X = O, NR ) have also been prepared from cyanamide and esters of type (321 Scheme 113) (79JHC961). 

Urea occurs as a colorless to white, prismatic, crystalline powder or as small, white pellets. It is commonly produced from C02 by ammonolysis or from cyanamide by hydrolysis. It is freely soluble in water and in boiling alcohol, but practi-... 

Salts of phenylcyanamide react with RsSiCl (R = Me, Ph) to give the carbodiimide R3SiN=C=NPh." Instead of silyl halides also trimethylsilylcyanideis used. In this manner a 90 % yield of bis(timethylsilyl)carbodiimide is obtained from cyanamide and trimethylsi-lylcyanide (1 min, rt). " ... 

The same carbodiimide is obtained from cyanamide and bis(diisopropylamino)chloro-phosphane in the presence of triethylamine (85% yield), and from the N-cyano-P-hydrogenoiminophosphoraneMe3SnCl adduct andbis(diisopropylamino)chlorophosphane (95 % yield). 

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