Cyanamide Cyanates

Cyanide is a known or suspected pollutant in approximately 24 pesticide processes. The primary raw materials that favor the generation of cyanides as either byproducts or impurities are cyanamides, cyanates, thiocyanates, and cyanuric chloride. Cyanuric chloride is used exclusively in the manufacture of triazine pesticides. 

Kaupp et al. also exploited heterogeneous reactions with CICN and BrCN in the quantitative synthesis of cyanamides, cyanates, thiocyanates and derivatives [26]. Gaseous acids were shown to form salts with strong and weak solid nitrogen bases. Solid hydrohalides are formed quantitatively by reaction with vapours of HCl, HBr and HI the same applies to di-bases such as o-phenylen-diamines. The products are much more easily handled than when they are formed in solution. The solid products can in turn be used in reactions with gaseous acetone to form the corresponding dihydrohalides of 1,5-benzodi-azepines [27]. 

Cyanamide, 109 see also Calcium Cyanamide Cyanate, potassium, 73 Cyanides, 71 et seq. Erlentneyer process for, 72 from ammonia, carbon and alkali metal, or salt, 73 from atmospheric nitrogen, 78, 79 from blast furnace gases, 36 from coal gas, 81, 8a from cyanamide, 66, 78 from ferro-cyanides, 7a, 73 from prussiates, 72 73 from schlempe, 76 from sodamide, 74, 75 statistics, 71 from stilpho-cyamdes, 75, 76... 

Kaupp, G., Schmeyers, J., and Boy, J. 1998. Quantitative gas-solid reactions with CICN and BrCN synthesis of cyanamides, cyanates, thiocyanates, and their derivatives. European Journal of Chemistry, 4 2467-2474. 

Silver Azide. Cyanide, Cyanamides, Cyanate Selenocyanate and Thiocyanate Argon... 

Cyanamide flush Cyan amides Cyanate Cyanazine... 

The nitrogen of aHphatic and aromatic amines is alkylated rapidly by alkyl sulfates yielding the usual mixtures. Most tertiary amines and nitrogen heterocycles are converted to quaternary ammonium salts, unless the nitrogen is of very low basicity, eg, ia tn phenylamine. The position of dimethyl sulfate-produced methylation of several heterocycles with more than one heteroatom has been examined (22). Acyl cyanamides can be methylated (23). Metal cyanates are converted to methyl isocyanate or ethyl isocyanate ia high yields by heating the mixtures (24,25). 

Reaction of lime and urea forms calcium cyanate [6860-10-2] (26) which is then converted to calcium cyanurate [32665-90-0], the latter gives calcium cyanamide at a higher temperature ... 

Similar differences are found for organic azides (e.g. MeN3). In ionic azides (p. 417) the N3 ion is both linear and symmetrical (both N-N distances being 116 pm) as befits a 16-electron species isoelectronic with CO2 (cf. also the cyanamide ion NCN, the cyanate ion NCO, the fulminate ion CNO and the nitronium ion N02 ). 

In summary, it has been established that all NMPs and NDPs are phosphorylated in reactions where calcium phosphate is present. However, no phosphorylation products are obtained when diphosphate (PP0 or tripolyphosphate (PPPi) is used instead of phosphate (Pi). Neither cyanamide nor dicyandiamide can be used instead of cyanate. 

Marcotrigiano et al.39 suggested that the desulfuration of thiourea in sodium hydroxide results in the formation of cyanamide, amidinourea, and guanidine at a pH below 12 they also suggested that the formed urea converts to ammonium cyanate and finally to ammonium carbonate (by hydrolysis). The pro-... 

Cyanamides, 3 157-171 23 107 economic aspects, 3 162-163 health and safety factors, 3 163-164 manufacture, 3 161 shipping and handling, 3 162 specifications and analysis, 3 163 Cyanate ester curing agents, 20 411 Cyanate ester resins, production of, 23 769 Cyanation, 9 313 Cyanazine, 23 321-322 Cyan couplers, in chromogenic chemistry, 19 252-253 Cyan dyes... 

Sodium compounds, 22 760-761, 762 as soap bar additives, 22 744 Sodium cyanamide, 8 184 Sodium cyanate, 8 184 Sodium cyanide, 8 183-184 analysis, 8 190 economic aspects, 8 189 health and safety factors, 8 190-191 manufacture, 8 187-189 properties, 8 184-187, 185t silver extraction via, 22 638, 646-647 uses, 8 191... 

Alkyl or aryl aminothiatriazoles (330) in contrast react with cyanates even at — 70°C to give 5-amidino substituted 1,2,4-thiadiazoles (331) weaker electrophiles, such as isothiocyanates, thiocyanates, and cyanamide do not react with aminothiatriazoles <85JOCl295>. 

Reaction of V,7V -diphenylthiourea with 2,4-dimethylphenyl cyanate to yield diphenylcarbodiimide and 0-(2,4-dimethylphenyl)thiocarbamate. Monosubstituted thioureas yield the cyanamide [76]. 

Aryl cyanates react with cyanamides to form (114), which reacts with a further equivalent of aryl cyanate to form the 2,4-bis(aryloxy)-l,3,5-triazine (115) in strongly alkaline conditions (Scheme 64) <67AG(E)206>. 

Subsequently, it was shown that the reaction was catalyzed by base (48M(79)106). Dicyandiamide reacts with nitriles (the most valuable method), amidines, cyanamides, ammonia, cyanates, thiocyanates, carboxylic acids and anhydrides to yield 1,3,5-triazines (Table 13). This synthetic route has been reviewed thoroughly several times (59HC(13)1, p. 219,61MI22000, p. 650, 73ZC408). The base-catalyzed reaction of dicyandiamide with alkyl or aryl nitriles (Scheme 65) proceeds via the imino ether anion and the rate determining step is solvent dependent. In DMSO the formation of the imino ether is rate determining, but in 2-methoxyethanol the reaction between the anion and dicyandiamide controls the rate (66T157). 

Cyanurea (called Cyanharnstoff, Allophansaure-nitrile, Cyansaureureid, or Cyanaminoformamidin Ger), NC.NH.C0.NH2 mw 85-07, N49-40% ndls, mp-softens dec at 100° can be prepd by interaction of K cyanate cyanamide in water soln, by action of Ba (OH)2 on dicyandiamide in w soln, and by action of aq HC1 on the Ag salt of dicy-animide (Ref 2). Cyanurea forms a large number of metallic salts (Ref 1)... 

The relationship between carbon dioxide, the cyanate ion, and the cyanamide ion is shown ... 

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