Nitration general methods

Originally, general methods of separation were based on small differences in the solubilities of their salts, for examples the nitrates, and a laborious series of fractional crystallisations had to be carried out to obtain the pure salts. In a few cases, individual lanthanides could be separated because they yielded oxidation states other than three. Thus the commonest lanthanide, cerium, exhibits oxidation states of h-3 and -t-4 hence oxidation of a mixture of lanthanide salts in alkaline solution with chlorine yields the soluble chlorates(I) of all the -1-3 lanthanides (which are not oxidised) but gives a precipitate of cerium(IV) hydroxide, Ce(OH)4, since this is too weak a base to form a chlorate(I). In some cases also, preferential reduction to the metal by sodium amalgam could be used to separate out individual lanthanides. 

Since the silver salts of the carboxylic acids are usually soluble in dilute nitric acid, they must be prepared by treating an aqueous solution of a neutral salt of the acid (and not the free acid itself) with silver nitrate solution. It is not practicable to attempt to neutralise the acid with sodium or potassium hydroxide solution, because the least excess of alkali would subsequently cause the white silver salt to be contaminated with brown silver oxide. The general method used therefore to obtain a neutral solution j to dissolve the acid in a small excess of ammonia solution, and then to boil the solution until all free... 

Nitration products. Although no general method of nitration can be given, the following procedure is wddely applicable. 

The diazonio group can also be replaced by —OH to yield a phenol and by —H to yield an arene. A phenol is prepared by reaction of the arenediazonium salt with copper(I) oxide in an aqueous solution of copper(ll) nitrate, a reaction that is especially useful because few other general methods exist for introducing an -OH group onto an aromatic ring. 

Nitration of aromatic rings by nitronium tetrafluoroborate is a general method. Fifty-seven arenes, haloarenes, nitroarenes,... 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

Test 1. When miconazole nitrate is tested according to the general method (2.2.14), the drug substance melts in the range 178-184 °C. 

Test 2. Examine miconazole nitrate by infrared absorption spectrophotometry according to the general method (2.2.24), comparing with the spectrum obtained with miconazole nitrate CRS. Examine the drug substance prepared as disc using potassium bromide R. 

Dissolve 0.35 g of miconazole nitrate in 75 mL of anhydrous acetic acid R, with slight heating, if necessary. Titrate with 0.1 M perchloric acid determining the end point potentiometrically, according the general method (2.2.20). Carry out a blank titration. One milliliter of 0.1 M perchloric acid is equivalent to 47.91 mg of Ci8H15Cl4N304. 

DIN 53 207 TI, T2 Bestimmung des Gehaltes an wasserloslichen Sulfaten, Chloriden und Ni-traten. ISO 787-13-1984 General methods of testing for pigments, Part 13 Determination of water-soluble sulphates, chlorides and nitrates. 

This procedure illustrates a general method for converting substituted pyrylium salts to nitrobenzene derivatives. The reaction has been the subject of several reviews. - The yields are generally high, and under these conditions only a single product is formed, in contrast to the nitration of 1,3,5-triphenyl-benzene. The preparation of 2,4,6-triphenylnitrobenzene from the corresponding pyrylium salt eliminates isomer separation problems, which are encountered when the direct nitration procedure is used. Also, labeled compounds can readily be prepared by this method. ... 

Regardless of the source, phenolic acids are ultimately broken down to gaseous products such as CO2 and methane. This breakdown occurs by three general methods (i) aerobic respiration, using molecular oxygen as an electron acceptor, the end product being CO2, (ii) anaerobic respiration with electron acceptors such as nitrate and (iii) anaerobic fermentation with phosphorylation reactions involving no external electron acceptor (50). 

In a nutshell, NENAs provide higher impetus at any given flame temperature than many conventional energetic ingredients and it is regarded as their most outstanding feature [165]. A general method for the manufacture of Alkyl NENAs [Structure (4.25)] is by the nitration of commercially available alkyl ethanolamine (Equation 4.20) ... 

The general methods for the production of the alkali metals are (1) Electrolytic processes involving the electrolysis of (a) the fused hydroxide, or (b) a fused salt— chloride, nitrate, cyanide, etc. (2) Chemical processes involving the reduction of hydroxide, or carbonate, or other salt with carbon, metal carbide, iron, calcium, magnesium, aluminium, etc. W. Spring 5 claims to have reduced a little potassium chloride by passing hydrogen over the salt at a red heat. 

The synthesis of pentaammine(carbonato)cobalt(III) salts is readily accomplished by an air-oxidation method starting with cobalt(II) nitrate and ammonium carbonate in aqueous ammonia.1 However, a suitable general method for making other types of monodentate amino(carbonato) metal salts is not available in the literature. The air-oxidation technique can be applied only to complexes where the ligands are all ammonia molecules or where the central metal ion is cobalt. 

Ammonium nitrate, NH4NOa.—The nitrate can be prepared by the general methods applicable to the ammonium salts. It is also produced by heating the nitrate of an alkali-metal with ammonium sulphate at 160° to 200° C., the fused ammonium nitrate being separated from the solid alkali-metal sulphate by centrifuging.11 Another method consists in cooling a concentrated solution of sodium nitrate and ammonium sulphate to —15° C., sodium sulphate being precipitated. On evaporation of the mother-liquor, most of the sodium sulphate is deposited addition of nitric acid to the clear solution causes crystallization of the ammonium nitrate.12 When sodium nitrate is... 

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