Carbon dioxide reactions with ammonia

Figure 7.12 outlines how hydantoin is produced during the synthesis of methionine depicted in Figure 7.11. Initially, the aminonitrile B is formed. With its amino group it adds to carbon dioxide, which—under the weakly basic reaction conditions—is followed by the formation of the carbamate ion D. In a fully analogous fashion, ammonia reacts with carbon dioxide to give ammonium carbamate (cf. Section 8.2). The intermediate D in Figure 7.12 permits the intramolecular and thus kinetically favored—i.e., fast—addition of the oxyanion to the C=N triple bond. The addition product is the negatively charged heterocycle F, which in...

The answer is c. (Murray, pp 307—346. Scriver, pp 1909-1964. Sack, pp 121-138. Wilson, pp 287-317.) The steps of the urea cycle are divided between the mitochondrial matrix and cytosol of liver cells in mammals. The formation of ammonia, its reaction with carbon dioxide to produce carbamoyl phosphate, and the conversion to citrulline occur in the matrix of mitochondria. Citrulline diffuses out of the mitochondria, and the next three steps of the cycle, which result in the formation of urea, all take place in the cytosol. Peroxisomes have single membranes, in contrast to the double membranes of mitochondria. They house catalase and enzymes for medium- to long-chain fatty acid oxidation. 

Treatment of (127) with sodium in liquid ammonia followed by ethylene diamine gave (128), while reaction with cyclohexylamine gave the tautomeric system (129). Reaction of (129) with metal acetates gave the metal complexes (130). The -position of (127) is acidic enough to be metallated with butyllithium, and upon reaction with carbon dioxide followed by hydrolysis, (131) was obtained in... 

The sodium acetylide solution thus prepared may be used for a variety of organic syntheses by the addition of alkyl halides, sulfates, sulfonates, ketones, aldehydes, and esters. Where a fine suspension of the dry acetylide is desired in an inert solvent such as ether or a hydrocarbon, the solvent is added to the ammonia solution and the mixture is stirred whde the ammonia is evaporated. Extra solvent must be used to replace that entrained by the ammonia, the last traces of which are removed by a period of refluxing. Such a suspension gives better yields of, for example, propiolic acid (by the reaction with carbon dioxide) than sodium acetylide prepared in any other way. 

Urea (CH4N2O), a common fertilizer, can be synthesized by the reaction of ammonia (NH3) with carbon dioxide ... 

The ammonia liberated by GLDH does not itself enter the urea cycle it must first be combined with carbon dioxide to form carbamoyl phosphate. This is an energy (ATP) consuming reaction ... 

Carbamoyl-phosphate synthetase (ammonia) [EC 6.3.4.16], also known as carbamoyl-phosphate synthetase I, catalyzes the reaction of two molecules of ATP with carbon dioxide, ammonia, and water to produce two molecules of ADP, orthophosphate, and carbamoyl phosphate. Carbamoyl-phosphate synthetase (glutamine-hydrolyzing) [EC 6.3.5.5], also known as carbamoyl-phosphate synthetase II, catalyzes the reaction of two molecules of ATP with carbon dioxide, glutamine, and water to produce two molecules of ADP, orthophosphate, glutamate, and carbamoyl phosphate. 

The Solvay process involves a series of partial reactions. The first step is calcination of calcium carbonate to form lime and CO2. Lime is converted to calcium hydroxide. The most crucial step of the process involves reacting brine solution with carbon dioxide and ammonia to produce sodium bicarbonate and ammonium chloride. Sodium bicarbonate converts to sodium carbonate. The calcium hydroxide and ammonium chloride react to form calcium chloride as the by-product. The partial reactions are shown below ... 

Using the relevant tables, find the solubilities of the salts that can form in an ammonia solution of sodium chloride saturated with carbon dioxide. Explain the sequence of the processes occurring in this reaction mixture. Recrystallize the product from warm water (about 50 G). 

In this experiment, we study the kinetics of the urea decomposition. As shown in equation (1), the products of the reaction are carbon dioxide, C02, and ammonia, NH3. Ammonia, being a base, can be titrated with an acid, HC1, and in this way we can determine the amount of NH3 that is produced. 

Summary Ammonium azide is easily prepared by mixing solutions of sodium azide, and aqueous ammonia. The mixture is then treated with carbon dioxide gas to precipitate sodium ion as sodium bicarbonate. The remaining ammonium azide stays in solution, and can be recrystallized from the reaction mixture. The collected crystals should then be dried in a desiccator as vacuum drying may result in loss of product from volatization air-drying the solid may also lead to loss in product. 

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