I Nitrate Reagent

Grind 5 g mercury(I) nitrate dihydrate with 100 ml water in a mortar and tranfer it to a storage vessel along with the sediment the supernatant is fit for use as long as the sediment remains white [1], 

The reagent may be stored for an extended period new reagent must be made up when the sediment becomes grey or yellow in color [1], 

The chromatograms are dried in a stream of warm air or at 105 °C for 10 min, cooled to room temperature and sprayed homogeneously with the spray reagent until they start to become transparent. 

Grey-black chromatogram zones are produced on a white background, usually appearing immediately but sometimes only after a few minutes. In the case of insecticides the chromatograms are heated after spraying [5]. 

Note Traces of ammonia from the mobile phase should be removed from the plate completely to avoid background discoloration (grey veil) [1]. If the layer is sprayed too heavily the initially grey-black chromatogram zones can fade again [2]. The reagent which is usually employed as a 1 to 2% solution [2, 3, 6, 7] can be treated with a few drops of nitric acid to clarify the solution [2]. 

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Barbiturate metabolites are more heavily colored by the mercury(I) nitrate reagent (exception allobarbital), while unaltered barbiturates react more sensitively to the mercury(II)-diphenylcarbazone reagent (q.v.) [1]. 

Mercaptoethanol reagent 380 Mercury cations 144,311 Mercury lamps 20, 22 ff emission lines 23, 24 -, high pressure 22 ff -, technical data 23 Mercury(I) nitrate reagent 337 Mercury(II) salt reagent 340 Mesaconic acid 61 Mesoporphyrin 101, 102 Metal cations 310—312,398 Metal complexes 248, 398 Methanol, dipole moment 97 Methine dyestuffs 360 4-Methoxyaniline see Anisidine 4-Methoxybenzaldehyde see Anisaldehyde Methoxybenzaldehyde derivatives 72 Methoxycinnamic acid 277... 

Filter paper moistened with mercury(I) nitrate solution may also be used this is blackened by ammonia. The mercury(I) nitrate reagent contains an excess of free nitric acid it is advisable, therefore, to add sodium carbonate solution dropwise and with stirring to about 1 ml of mercury(I) nitrate solution until a slight permanent precipitate is produced. The solution is centrifuged and the centrifugate is employed for the preparation of mercury(I) nitrate paper. ... 

Other reagents that convert benzylic halides to aldehydes are 2-nitropropane-NaOEt in EtOH,336 mercury(I) nitrate followed by ethanolic alkali,337 and pyridine followed by p-nitrosodimethylaniline and then water. The last procedure is called the Krohnke reaction. Primary halides in general have been oxidized to aldehydes by trimethylamine oxide,338 by... 

In most of the examples of superelectrophilic reactions involving Lewis acids, they are conducted using an excess of the Lewis acid. This is in accord with electrophilic solvation by the Lewis acid, i.e. activation of the electrophile requires interaction with two or more equivalents of Lewis acid. As an example, superelectrophilic nitration can be accomplished with NO2CI and at least three equivalents of AICI3 (eq 23).46 This powerful nitrating reagent involves a superelectrophilic complexed nitronium ion (33). 

Zirconium phosphate. Reject. Test if all phosphate has been precipitated by the addition of a drop of the zirconium(IV) nitrate reagent. Add about 0-5 g solid NH4C1, heat to boiling, add a slight excess of dilute NH3 solution (i.e. until the odour of NH3 is permanent in the boiling solution), boil for 2-3 minutes and filter. ... 

Ammonium was tested for in preliminary test 6 (Section V.2). By heating the original substance with NaOH solution, NH3 will be evolved from ammonium salts. The NH3 gas may be identified by its odour, by its action upon red litmus paper or upon filter paper moistened with mercury(I) nitrate solution, or by the tannic a cid-silver nitrate test (Section III.38, reaction 7). The insertion of a loose plug of cotton wool in the upper part of the tube will eliminate the danger of NaOH solution spray affecting the reagent paper. 

Arsenite. (i) Action of H2S upon acid solution (III. 12, 1). (ii) Silver nitrate solution test (III. 12, 2), and absence of precipitate with magnesium nitrate reagent (III.12, 3) or on boiling with ammonium molybdate solution and nitric acid, (iii) Bettendorff s test (III.12, 6). 

Arsenate, (i) Action of H2S on acid solution (III.13, 1), and silver nitrate solution test upon neutral solution (III.13, 2). (ii) Magnesium nitrate reagent test (ffl.13, 3). (iii) Ammonium molybdate test (III.13, 4). 

The reagent system consists of 1.1 to 2.0 equivalents of silver(I) nitrate, perchlorate, tetrafluoro-borate, or triflate in nucleophilic solvents such as water (cosolvents acetone or acetonitrile) or alcohols, respectively, if allylic alcohols or allylic alkyl ethers, respectively, are desired. 

Treatment of bicyclo[4.1.0]heptan-2-ols with perchloric acid in acetic acid caused very clean rearrangement with formation of cyclohept-3-enyl acetates (Table 1). Only in the case of cxo-7-methylbicyclo[4.1.0]heptan-2-ol was the cyclohex-2-enyl acetate the major product probably because the 7-methyl group conferred additional stabilization on the carbocation formed by j0-scission of the outer cyclopropane bond. The same type of reactant could be oxidatively rearranged using pyridinium chlorochromate to afford cyclohepten-4-ones, together with (chloromethyl)cyclohexenes. However, if the chloride in the reagent was replaced with tetrafluoroborate, or if pyridinium chlorochromate was used with silver(I) nitrate, formation of the substituted cyclohexenes was completely suppressed, e.g. formation of 7 from 6, although the reported yields were low. ... 

Most spectrophotometric methods for determining nitrate are based either on I), nitration or oxidation of appropriate organic reagents to form coloured compounds or on, 2), reduction of NO.i to NO2 or NH3 with subsequent determination of this species. Prevalent among the methods belonging to the first group are those using phenoldisulphonic acid, and xylenols. 

THE NITRATION OF AROMATIC COMPOUNDS has been studied for decades, and benzene and its derivatives have been used almost exclusively as the substrates (I, 2). Nitric acid, usually in sulfuric acid, has generally been the nitrating reagent the nitronium ion, N02 +, has presumably been the specific nitrating agent. Nitric acid and the nitronium are both N(V) species. 

Reduction of tetrazolo[l,5-ft][l,2,4]triazine derivatives (16) was also studied <76JOC4l>. Catalytic hydrogenation resulted in partial reduction at the C(7)—N(8) bond to give (17). Sodium borohy-dride, in contrast, led to the formation of a tetrahydro derivative (19). Behavior of both reduction products (17) and (19) towards nitration reagent was also studied, and nitrations of the NH groups have been detected (i.e., (17) gave the mononitro compound (18), whereas (19) afforded the dinitro derivative (20)). 

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