Ammonia, hazards synthesis

Ammonia, Ammonium nitrate, Diphenyl carbonate Buzard, J. et al., J. Amer. Chem. Soc., 1952, 74, 2925-2926 During the synthesis of 15N-labelled urea by interaction of labelled ammonium nitrate, liquid ammonia and diphenyl carbonate in presence of copper powder, a series of explosions of the refrigerated sealed tubes was encountered. This was almost certainly caused by condensation of traces of oxygen in the tubes cooled to — 196°C dining condensation of ammonia before sealing the tubes. Cooling to —80°C would have been adequate and have avoided the hazard. 

ID S is synthesized by the reaction of ammonia with maleic anhydride in water. The synthesis of EDDS and IDS is also in accordance with the 3rd Principle of Green Chemistry Design Less Hazardous Chemical Synthesis, although they are still not perfectly green as there still some hazardous components. This can be a difficult principle to achieve completely as many reactive chemicals in the chemist s toolbox are often hazardous. 

The synthesis which forms the basis of production at Hoffinann-La Roche (Fig. 5) proceeds via the pyrimidinenitrile [698-29-3] (26) made from malononitrile, trimethylorthoformate, ammonia, and acetonitrile (42,43). High pressure catalytic reduction of the nitrile furnishes diamine (16). The overall sequence is short, highly efficient, and generates almost no waste. However, malononitrile is a relatively expensive and hazardous three-carbon source. 

Hazardous Decomp. Prods. Heated to decomp, emits CO, CO2, NOx, ammonia, traces of organic compds. inc. hydrogen cyanide, nitriles, isocyanates, nitrosamines, amines NFPA Health 3, Flammability 4, Reactivity 0 Uses Intermediate in organic synthesis intermediate for water-gel explosives, accelerators, pharmaceuticals, insecticides, N-methylpyrrolidine, methylalkanolamines, surface active agents, fungicides in tanning component of photographic developers and paint removers fuel additive prod, of dyes polymerization inhibitor rocket propellant See also Methylamine... 

Catalytic Dehydrogenation of Diethanolamine Monsanto has developed a new method for production of the herbicide that eliminates most manufacturing hazards and all use of cyanide, ammonia, and formaldehyde in the synthesis of the key intermediate, DSIDA. Monsanto s novel catalytic synthesis of DSIDA uses a copper catalyst, and is safer because it is endothermic, produces higher overall yield, and has fewer process steps. 

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