Ammonia Ammonium acetate

Some nucleophiles open the pyrylium ring to give intermediates which are capable of spontaneous or add-induced cyclization to a new ring. The conversion of pyrylium salts into pyridines is the most thoroughly studied example and was first described in 1911 (B-64MI22300). Ammonia, ammonium acetate or carbonate react with pyrylium salts such... 

Some a-hydroxy carbonyl compounds when heated with ammonia, ammonium acetate or formate, or formamide have been shown to give pyrazines the reaction presumably proceeds through the a-amino carbonyl compound. 

Ammonia Ammonium acetate Ammonium carbonate Ammonium phosphate ... 

Aluminum Ammonia Ammonium acetate Ammonium hydroxide Ammonium nitrate Ammonium perchlorate Aniline Barium chlorate Bromopicrin Calcium nitrate Calcium stearate L-Camphor m-Cresol Dextrin Dicyandiamide Dinitrotoluene 2,4-Dinitrotoluene Ethylene glycol Ethylene glycol dinitrate Hexachloroethane... 

Sodium gluconate nutrient, medicine inositoi Thiamine nutrient, microbiai fermentation Ammonia Ammonium acetate Ammonium phosphate Ammonium phosphate, dibasic Ammonium sulfate... 

The labeled albumin fraction (600 mg in 8.5 ml) is extensively digested with trypsin (36 mg) at pH 7.7 to 7.9. The tryptic digest is subjected to gel filtration on a Sephadex G-50 column (3.2 X 90 cm) in 0.1 M ammonia-ammonium acetate at pH 9.2. The main part of the labeled peptides is eluted at the total volume of the column. This peptide fraction is further fractionated by ion-exchange chromatography on a SE-... 

Sephadex column (1.6 X 40 cm) using pH gradient elution. The gel is equilibrated with 0.1 Af acetic acid-0.1 M formic acid buffer, pH 3.0, and the peptides are eluted by increasing the pH of the eluent with 0.4 M ammonia. One main peptide labeled with fluorescein is eluted at pH 4.3. A complete purification of the labeled peptide is performed by gel filtration on a Sephadex G-25 column (1.5 X 40 cm) in 0.1 M ammonia-ammonium acetate at pH 9.2. 

Amino acid analysis after acid hydrolysis of the pure peptide yields leucine and tyrosine in a 1 1 molar ratio. The peptide material (100 nmoles) is digested with carboxypeptidase A (10 /tg) at pH 8.3 and 37° for 2 hr. The digestion mixture is then passed through a Sephadex G-25 column (1.5 X 30 cm) in 0.1 M ammonia-ammonium acetate at pH 9.2. A complete separation of the peptide fragments is obtained. On the basis of N-terminal and amino acid analysis data on the peptide fragments, and from the known sequence data of bovine serum albumin, it has been concluded that the labeled peptide is the Tyr-Leu-Tyr sequence of residues 137-139 with the fluorescein molecule attached to Tyr-137. 

Amidines react with nucleophiles like ammonia, amines or hydrazine, in a displacement reaction . Application of this reaction for the removal of the acetamidine group was described in the literature. Side-reactions are avoided by running the reaction at room temperature for 8 hours, employing as the nucleophile an ammonia-ammonium acetate buffer (pH 11-3). 

An excess of acetic acid is usually added before heating in order to repress the hydrolysis (and also the thermal dissociation) of the ammonium acetate, thus preventing the escape of ammonia. The excess of acetic acid, together with the water, is removed by slow fractional distillation. The method is rarely used except for the preparation of acetamide. 

The versatility of this reaction is quite apparent. One can use ammonium acetate to make MDA or amphetamine, or methylamine in methanol for MDMA. But methylamine is optimal because it gives higher yield and less byproducts. Also, if ammonium acetate is used, one must use either ammonia (NH3) or a primary amine (any of one s choosing. Strike supposes) in place of the triethyla-mine in the reaction. 

The covalent character of mercury compounds and the corresponding abiUty to complex with various organic compounds explains the unusually wide solubihty characteristics. Mercury compounds are soluble in alcohols, ethyl ether, benzene, and other organic solvents. Moreover, small amounts of chemicals such as amines, ammonia (qv), and ammonium acetate can have a profound solubilizing effect (see COORDINATION COMPOUNDS). The solubihty of mercury and a wide variety of mercury salts and complexes in water and aqueous electrolyte solutions has been well outlined (5). 

Both normal or neutral ammonium acetate [631-61-8], NH4C2H2O2, and the acid salt are known. The normal salt results from exact neutralization of acetic acid using ammonia the acid salt is composed of the neutral salt and acetic acid. 

Isolation of dry, normal ammonium acetate, prepared by neutralizing acetic acid with anhydrous ammonia or ammonium carbonate, is difficult because of ammonia loss during evaporation of water. Consequendy, commercial grades of ammonium acetate are often mixtures of the neutral and acid salts, or are suppHed as ammonium acetate solution [8013-61-4]. 

Ammonium acetate has limited commercial uses. It serves as an analytical reagent, and in the production of foam mbber and vinyl plastics it is also used as a diaphoretic and diuretic in pharmaceutical appHcations. The salt has some importance as a mordant in textile dyeing. In a hot dye bath, gradual volatilization of ammonia from the ammonium acetate causes the dye solution to become progressively more acidic. This increase in acidity enhances the color and permanence of the dyeing process. 

For binder preparation, dilute hydrochloric or acetic acids are preferred, because these faciUtate formation of stable silanol condensation products. When more complete condensation or gelation is preferred, a wider range of catalysts, including moderately basic ones, is employed. These materials, which are often called hardeners or accelerators, include aqueous ammonia, ammonium carbonate, triethanolamine, calcium hydroxide, magnesium oxide, dicyclohexylamine, alcohoHc ammonium acetate, and tributyltin oxide (11,12). 

Zinc oxide [1314-13-2] (mol wt 81.37 Cl Pigment White 4, Cl No. 77947) is a white or yellowish white amorphous, odorless powder with pH 6.95—7.37. It is practically iasoluble in water but soluble in dilute acetic acid, mineral acids, ammonia, ammonium carbonate, and alkaU hydroxides. 

Treatment of a-hydroxy-ketones or -aldehydes with ammonium acetate (65BSF3476, 68BSF4970) results in the formation of dihydropyrazines, presumably by direct amination of the hydroxyketone followed by self-condensation (79AJC1281). Low yields of pyrazines have been noted in the electrolysis of ketones in admixture with KI and ammonia, and again it appears probable that the a-aminoketone derived by way of the a-iodoketone is the intermediate (69CI(L)237>. 

Reagents such as water, ammonia, hydrochloric acid, nitric acid, perchloric acid, and sulfuric acid can be purified via distillation (preferably under reduced pressure and particularly with perchloric acid) using an allglass still. Isothermal distillation is convenient for ammonia a beaker containing concentrated ammonia is placed alongside a beaker of distilled water for several days in an empty desiccator so that some of the ammonia distils over into the water. The redistilled ammonia should be kept in polyethylene or parafrin-waxed bottles. Hydrochloric acid can be purified in the same way. To ensure the absence of metal contaminants from some salts (e.g. ammonium acetate), it may be more expedient to synthesise the salts using distilled components rather than to attempt to purify the salts themselves. 

A. a,a-Dicyano- -ethyl-fi-methylglutarimide. In a 2-1. round-bottomed flask are placed 452 g. (4.0 moles) of ethyl cyanoace-tate, 144 g. (2.0 moles) of methyl ethyl ketone, 2 g. of ammonium acetate, and 800 ml, of 95% ethanol which contains 80 g. (4,7 moles) of anhydrous ammonia (Notes 1 and 2). The flask is stoppered and placed in a refrigerator. 

AMMO 2.5 EC , cypermetlu-in, 13 Ammonia, 13 Ammonium acetate, 13 Ammonium arsenate, 13 Ammonium benzoate, 13 Ammonium bicarbonate, 13 Ammonium bifluoride, 14 Ammonium bisulfite, 14 Ammonium carbamate, 14 Ammonium carbonate, 14 Ammonium chloride, 14 Ammonium chlorplatmate, 14 Ammonium clu omate, 14 Ammonium citrate, 14 Ammonium diclu omate, 14 Ammonium fluoride, 14 Ammonium fomiate, 15 Ammonium hexafluorosilicate, 15 Ammonium hydroxide, 15 Ammonium metavanadate, 15 Ammonium molybdate, 15 Ammonium nitrate, 15 Ammonium oxalate, 15 Ammonium perfluorooctanoate, 15 Ammonium persulfate, 15 Ammonium phosphate, 15 Ammonium picrate, 16 Ammonium salicylate, 16... 

The o-aminophenylpropiolic acid 4 (20 g) in water (60 mL) and aqueous ammonia (9 mL, d = 0.88) was added with shaking during 15 minutes to a mixture prepared from ferrous sulfate (220 g), water (440 mL), and aqueous ammonia (110 mL, d = 0.88). After 45 minutes, with occasional shaking but no external cooling, the suspension was filtered. The residue was washed with water, and the combined filtrates were treated with ammonium acetate (60 g) and made weakly acidic with acetic acid. The solution was then cooled to 0°C by addition of crushed ice, and then made acidic to Congo-red with concentrated hydrochloric acid (70-80 mL). Additional hydrochloric acid (20 mL, 2 N) was immediately added, and the turbid solution which resulted was diazotized with 20% aqueous sodium nitrite, after which the mixture was kept at 70°C. The cinnoline acid 6 was separated over 45 minutes as a dark brown, granular solid (12.5 g), m.p. 260-265°C. ... 

The relatively poor resonance activation of the 2-Le-3-aza orientation in bicyclics (cf. Section IV, A) is illustrated by nucleophilic substitutions below. Vigorous conditions are required for methoxylation (110°, 17 hr, quantitative yield) of 3-bromocinnoline and for amination (aqueous ammonia, copper sulfate, 20 hr, high yield) of 3-bromo- (at 130°) or of 3-chloro-derivatives (at 165°). 3,4-Dichlorocinnoline gives predominantly 4-substitution in hydra-zination (90% yield, 20°, 4 days in alcohol), amination (70% yield, 150°, 22 hr in alcohol), and hydroxylation (50% yield, 150°, 22 hr, aqueous ammonia). The poorer-leaving phenoxy group in 3-chloro-4-phenoxycinnoline, is displaced with ammonium acetate (160°, few mins, 60% yield). ... 

The reaction of relatively simple starting materials, coumarin 40, piperidone 37 and ammonium acetate, leads in a single step to the complex bridged tetracyclic compound 44. The reaction can be rationalized by assuming formation of the iminc 38 from reaction of 37, with ammonia. Conjugate addition of the eneamine-like tautomer 39 to the excellent Michael acceptor 40 will... 

Balabanov et al. [499] investigated the efficiency of different solutions for the washing of niobium hydroxide. The effectiveness of water and solutions of ammonia, NH4OH, ammonium acetate, CH3COONH4, and ammonium carbonate, (NH4)2C03, were tested. It was shown that ammonium acetate interacts with solid ammonium oxyfluoroniobates yielding niobium oxide even at temperatures as low as 125°C. The interaction that takes place between the solid components can be presented as follows (144) ... 

Hence, water, ammonia, hydrogen fluoride and carbon dioxide separate from the mixture into the gaseous phase. However, despite the possibility of a solid-state interaction, the application of ammonium acetate solutions for washing of... 

Ammonia solutions are significantly more efficient than ammonium acetate as washing reagents. The process of fluorine content reduction is related to subsequent hydrolysis of fluoride and oxyfluoride contaminants by ammonia. 

Either the Mohr titration or the adsorption indicator method may be used for the determination of chlorides in neutral solution by titration with standard 0.1M silver nitrate. If the solution is acid, neutralisation may be effected with chloride-free calcium carbonate, sodium tetraborate, or sodium hydrogencarbonate. Mineral acid may also be removed by neutralising most ofthe acid with ammonia solution and then adding an excess of ammonium acetate. Titration of the neutral solution, prepared with calcium carbonate, by the adsorption indicator method is rendered easier by the addition of 5 mL of 2 per cent dextrin solution this offsets the coagulating effect of the calcium ion. If the solution is basic, it may be neutralised with chloride-free nitric acid, using phenolphthalein as indicator. 

Beryllium is sometimes precipitated together with aluminium hydroxide, which it resembles in many respects. Separation from aluminium (and also from iron) may be effected by means of oxine. An acetic (ethanoic) acid solution containing ammonium acetate is used the aluminium and iron are precipitated as oxinates, and the beryllium in the filtrate is then precipitated with ammonia solution. Phosphate must be absent in the initial precipitation of beryllium and aluminium hydroxides. 

The precipitate is soluble in free mineral acids (even as little as is liberated by reaction in neutral solution), in solutions containing more than 50 per cent of ethanol by volume, in hot water (0.6 mg per 100 mL), and in concentrated ammoniacal solutions of cobalt salts, but is insoluble in dilute ammonia solution, in solutions of ammonium salts, and in dilute acetic (ethanoic) acid-sodium acetate solutions. Large amounts of aqueous ammonia and of cobalt, zinc, or copper retard the precipitation extra reagent must be added, for these elements consume dimethylglyoxime to form various soluble compounds. Better results are obtained in the presence of cobalt, manganese, or zinc by adding sodium or ammonium acetate to precipitate the complex iron(III), aluminium, and chromium(III) must, however, be absent. 

Weak acids with weak bases. The titration of a weak acid and a weak base can be readily carried out, and frequently it is preferable to employ this procedure rather than use a strong base. Curve (c) in Fig. 13.2 is the titration curve of 0.003 M acetic acid with 0.0973 M aqueous ammonia solution. The neutralisation curve up to the equivalence point is similar to that obtained with sodium hydroxide solution, since both sodium and ammonium acetates are strong electrolytes after the equivalence point an excess of aqueous ammonia solution has little effect upon the conductance, as its dissociation is depressed by the ammonium salt present in the solution. The advantages over the use of strong alkali are that the end point is easier to detect, and in dilute solution the influence of carbon dioxide may be neglected. 

Reagents. In view of the sensitivity of the method, the reagents employed for preparing the ground solutions must be very pure, and the water used should be re-distilled in an all-glass, or better, an all-silica apparatus the traces of organic material sometimes encountered in demineralised water (Section 3.17) make such water unsuitable for this technique unless it is distilled. The common supporting electrolytes include potassium chloride, sodium acetate-acetic acid buffer solutions, ammonia-ammonium chloride buffer solutions, hydrochloric acid and potassium nitrate. 

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