Nitrite iodide oxidation

Despite the reactivity of carbazole cation-radicals, that of 9-ethylcarbazole has been trapped by nucleophiles, e.g., I", NO2,475 Thus, iodo and nitro derivatives of 9-ethylcarbazole result, along with 9,9 -diethyl-3,3 -bicarbazole, when 9-ethylcarbazole is oxidized by iodine in the presence of iodide and nitrite.473 Oxidation in the absence of nucleophiles, e.g., by nitrosonium tetrafluoroborate, permits the synthesis of the cation-radical fluoroborate salts of the 3,3 -bicarbazoles476 The reactivity of the cation-radical of 9-vinylcarbazole has been reviewed recently.11,477... 

Generally liquid ammonia is a good solvent for many salts, such as nitrates, nitrites, iodides, cyanides, thiocyanides, and acetates. Ammonium salts are especially soluble. The hydroxides, fluorides, and salts with di- and trivalent anions, such as oxides and sulfides, in general are insoluble. Apart from alkali metals, some other metals and nonmetals are also soluble. A compilation of the solubilities of organic compounds in liquid ammonia shows notable solubility of saccharoses [1417],... 

Methyl iodide, 176 nitrate, 198 nitrite, 196 oxide, 169 Metliylamine, 206 Methylene bichloride, 174 Methylia, 205 Milk. 350 Minium. 119 Mixtures, 9 Molecule, 7, 11 Molybdenum, 104 Mmiamides, 206 Monsmines, 205 Monochtormethyl chloride, 174 Monoebtorobensene, 301 Hononitrobonsol 2, 81H Morphine, 334 Mucin, 3 ... 

Nucleophilic displacement of iodide by the nitrite ion in 1-iodo-17/. l//,2//,2W-perfluoroalkanes affords the 1-nitro analogue (equation 4). Oxidative nitration of the 1-mtro-l//, l//,2//.2//-perfluoroalkane with tetranitromethane yields the ge/n-dinitro compound [4. ... 

Nitric oxide is the simplest thermally stable odd-electron molecule known and, accordingly, its electronic structure and reaction chemistry have been very extensively studied. The compound is an intermediate in the production of nitric acid and is prepared industrially by the catalytic oxidation of ammonia (p. 466). On the laboratory scale it can be synthesized from aqueous solution by the mild reduction of acidified nitrites with iodide or ferrocyanide or by the disproportionation of nitrous acid in the presence of dilute sulfuric acid ... 

It has been suggested that the initial formation of iodine on addition of iodide to a diazonium salt solution is caused by oxidation of the iodide by excess nitrite from the preceding diazotization. Packer and Taylor (1985) demonstrated that, if urea was added as a nitrite scavenger (see Sec. 2.1) to a diazotization solution, that solution produced iodine much more rapidly than a portion of the same diazonium salt solution not containing urea, but eventually the latter reaction too appeared to follow the same course. This confirms the role of excess nitrite, and suggests that the iodo-de-diazoniation steps only occur in the presence of iodine or triiodide (I -). The same authors also found that iodo-de-diazoniation is much slower under nitrogen. All these observations are consistent with radical-chain processes, but not with a heterolytic iodo-de-diazoniation. 

C03-0109. The following pairs of substances are quite different despite having similar names. Write correct formulas for each, (a) sodium nitrite and sodium nitrate (b) potassium carbonate and potassium hydrogen carbonate (c) iron(II) oxide and iron(IIt) oxide and (d) iodine and iodide ion. 

Cyanide and thiocyanate anions in aqueous solution can be determined as cyanogen bromide after reaction with bromine [686]. The thiocyanate anion can be quantitatively determined in the presence of cyanide by adding an excess of formaldehyde solution to the sample, which converts the cyanide ion to the unreactive cyanohydrin. The detection limits for the cyanide and thiocyanate anions were less than 0.01 ppm with an electron-capture detector. Iodine in acid solution reacts with acetone to form monoiodoacetone, which can be detected at high sensitivity with an electron-capture detector [687]. The reaction is specific for iodine, iodide being determined after oxidation with iodate. The nitrate anion can be determined in aqueous solution after conversion to nitrobenzene by reaction with benzene in the presence of sulfuric acid [688,689]. The detection limit for the nitrate anion was less than 0.1 ppm. The nitrite anion can be determined after oxidation to nitrate with potassium permanganate. Nitrite can be determined directly by alkylation with an alkaline solution of pentafluorobenzyl bromide [690]. The yield of derivative was about 80t.with a detection limit of 0.46 ng in 0.1 ml of aqueous sample. Pentafluorobenzyl p-toluenesulfonate has been used to derivatize carboxylate and phenolate anions and to simultaneously derivatize bromide, iodide, cyanide, thiocyanate, nitrite, nitrate and sulfide in a two-phase system using tetrapentylammonium cWoride as a phase transfer catalyst [691]. Detection limits wer Hi the ppm range. 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

The following alternative procedure may be used to prepare a solution of disodium hydroxylaminedisulfonate. Sodium nitrite (15 g., 0.217 mole) and 41.6 g. (0.40 mole) of sodium bisulfite are added to 250 g. of ice. With stirring, 22.5 ml. (0.40 mole) of acetic acid is added all at once and the mixture is stirred for 90 minutes in an ice hath. At the end of the stirring period the reaction solution is pH 5 and a potassium iodide-starch test is negative. A solution of 50 g. (0.47 mole) of sodium carbonate in water (total volume 250 ml.) is added. This buffered solution of disodium hydroxylaminedisulfonate may be used for electrolytic oxidation. 

The reaction of a -halocarboxylic acids with sodium nitrite has been used to synthesize ni-tromethane, nitroethane and nitropropane, although the reaction fails for higher nitroalkanes. " A number of other reactions have been reported which use nitrite anion as a nucleophile, including (1) reaction of alkyl halides with potassium nitrite in the presence of 18-crown-6, (2) reaction of alkyl halides with nitrite anion bound to amberlite resins, (3) synthesis of 2-nitroethanol from the acid-catalyzed ring opening of ethylene oxide with sodium nitrite, and (4) reaction of primary alkyl chlorides with sodium nitrite in the presence of sodium iodide. ... 

Marchand and co-workers reported a synthetic route to TNAZ (18) involving a novel electrophilic addition of NO+ NO2 across the highly strained C(3)-N bond of 3-(bromomethyl)-l-azabicyclo[1.1.0]butane (21), the latter prepared as a nonisolatable intermediate from the reaction of the bromide salt of tris(bromomethyl)methylamine (20) with aqueous sodium hydroxide under reduced pressure. The product of this reaction, A-nitroso-3-bromomethyl-3-nitroazetidine (22), is formed in 10% yield but is also accompanied by A-nitroso-3-bromomethyl-3-hydroxyazetidine as a by-product. Isolation of (22) from this mixture, followed by treatment with a solution of nitric acid in trifluoroacetic anhydride, leads to nitrolysis of the ferf-butyl group and yields (23). Treatment of (23) with sodium bicarbonate and sodium iodide in DMSO leads to hydrolysis of the bromomethyl group and the formation of (24). The synthesis of TNAZ (18) is completed by deformylation of (24), followed by oxidative nitration, both processes achieved in one pot with an alkaline solution of sodium nitrite, potassium ferricyanide and sodium persulfate. This route to TNAZ gives a low overall yield and is not suitable for large scale manufacture. 

Nitromethane has been prepared by the action of methyl iodide on silver nitrite 2 by the action of methyl sulfate on potassium nitrite 3 by the oxidation of methylamine by Caro s reagent 4 by the interaction of potassium nitrite and potassium chloroacetate,5 or, preferably,1 the corresponding sodium salts.6 The use of the calcium salts was found to be of no advantage.1 The only one of the above methods to be studied was the interaction of the sodium salts in boiling aqueous solution. 

Assemble an apparatus for preparing nitrogen(n) oxide (Fig. 86ft). Pour a concentrated solution of sulphuric acid into wash bottles 7, and fill columns 8 with phosphoric anhydride applied onto glass wool. Dissolve 15 g of potassium nitrite and 7.5 g of potassium iodide inJ75 ml of water. Pour the solution into flask 6. Pour a 50% sulphuric acid solution into dropping funnel 5. 

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