Cyanamides, addition ammonia

Urea is also used as feed supplement for mminants, where it assists in the utilization of protein. Urea is one of the raw materials for urea—formaldehyde resins. Urea (with ammonia) pyrolyzes at high temperature and pressure to form melamine plastics (see also Cyanamides). Urea is used in the preparation of lysine, an amino acid widely used in poultry feed (see Amino acids Feeds and feed additives, petfoods). It also is used in some pesticides. 

Additions. The addition reactions of ammonia and amines to the cyanamide nitrile group have been thoroughly studied (15). For optimum conditions, the reaction should be carried out ia an aqueous medium at about 140°C. Gradual addition of the cyanamide to the amine salt minimises dimerization. 

Hydrolysis of cyanamides 6-13 Addition of ammonia to aldehydes 6-15 Reductive alkylation of ammonia or amines... 

Investigations by Malinowska et al. [110] have shown that absorption can be used to recover 90% of ammonia that is vaporized during chemical bath deposition of cadmium sulfide thin layers from which concentrated solutions with more than lOmolL-1 of pure ammonia can be obtained. Additionally, a cake with mixed cadmium sulfide-cadmium cyanamide is produced, from which cadmium can be recovered hydrochemically as cadmium sulfate [111]. The global process recovers up to 99.999% of cadmium and generates only solid sulfur and a liquid effluent containing traces of cadmium. 

Cyanamides, alcoholysis, 648 hydrolysis, 647, 680 Cyanides, acylation, 348 addition, of alcohols to, 634 of ammonia or amines to, 635 of olefins to, 571 alcoholysis, 485, 542 alkylation, 599 amination, 636 carbethoxylation, 489 condensation to /3-iminonitriles, 730 hydrolysis, to acids, 412 to amides, 570 preparation, 590... 

Guanidines are also obtained from carbodiimides (which are isomeric with cyanamides) since these react extremely readily with ammonia or amines. Thus, for instance, 7V,7V/,7V//-triphenylguanidine is formed exothermally when diphenylcarbodiimide is mixed with aniline.47 The analogous addition of phenylhydrazine to diphenylcarbodiimide, giving A,A -diphenyl-A"-(phenyl-amino)guanidine, forms the first step in the synthesis of nitrone.48... 

Guanidine from Cyanamide. Ammonia adds to cyanamide to form guanidine. It is presumed that addition occurs at the —C=N group with the formation of the amidine. 

This ammonia may then be oxidized to nitric acid, which may be neutralized with additional ammonia to form ammonium nitrate. Such is the proposed ojieration of the U. S. Nitrate Plant No. 2 at Muscle Shoals, Alabama. In order to give a clearer picture of the cyanamide process, there follows an equipment description of this plant, the only cyanamide plant in the United States. 

Guanidine derivatives of tetrahydroisoquinoline are generally prepared by the route shown in Scheme 5.21. The von Braun reaction converts the secondary amine (84) into the cyanamide (85) and hydrogen sulphide addition in pyridine-triethylamine gives the thiourea (86). Alkylation with bromoethane and treatment with ammonia complete the preparation of debrisoquin (87) and guanisoquin (88) [95], Recently, direct reaction of (85) with anhydrous ammonia to give (87) has been achieved [96]. The two guanidines are antihypertensives of which debrisoquin is the more useful. It appears to act in part by inhibition of neuronal monoamine oxidases [97]. 

Given that the BASF ammonia works capacity remained small and that little experience had been gained with the Haber-Bosch process, Emil Fischer considered it unavoidable in October 1914 that cyanamide production also be developed on a massive scale in addition to the BASF-ammonia in Oppau. Caro agreed in principle, but because the Trostberg works could not be expanded without further ado because of their dependence on the existing water power there, he insisted on the condition that new electrical plants be built in order to supply the necessary power for cyanamide production elsewhere. Fischer established immediate contact between him and Hugo Stinnes, who had an ulterior motive to join with the constellation of interests around Caro, since the enterprise could prove lucrative if it drew on the incompletely exploited power from his Rheinisch-Westfalische Elektrizitatswerk AG. ... 

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