Nitrate Maine

The importance of a primary steric effect in the nitration of alkyl-benzenes has been mentioned ( 9.1.1). The idea was first introduced by Le Fevre to account for the fact that -alkyltoluenes (alkyl = Et, -Pr,68a t-Bu ) are nitrated mainly adjacent to the methyl group. Without the rate data reported for the alkylbenzenes the effect might equally well have been accounted for by hyperconjugation. 

SULEURLESS GUNPOWDER A grade of gunpowder in which the sulfur is omitted and the proportion of charcoal is increased to maintain the correct fuel balance against the potassium nitrate. Mainly used in hreworks where there may be compatibility issues due to sulfur (e.g. in the proximity of chlorates). 

MIXTURES WITH NITRATES-MAINLY WITH AMMONIUM NITRATE... 

Almost simultaneously Voigt [25] recommended using mixtures of nitrates (mainly sodium nitrate) with salts of nitrophenolsulphonic acids (e.g. mononitrophenol-and mononitrocresolsulphonates) or salts of mononitronaphthalenesulphonic acid. He proposed mixing 25% of the aqueous solution with 75% of sodium nitrate. 

Thiophene is nitrated by mild nitrating agents such as acetyl or benzoyl nitrate, mainly in the... 

Nitro-2-phenylindoles are obtained by electrophilic ipso-nitration of arylazo, hydroxymethyl, and acyl groups on treatment with two equivalents of 70% nitric acid in acetic acid at 25°C. No attack on the phenyl ring is observed under these conditions [80MI1 81JCS(P2)628]. Indolenines undergo nitration mainly at the 5-position (77-85%) (64TL803). 

Thiophene is nitrated by mild nitrating agents such as acetyl or benzoyl nitrate, mainly in the 2-position. The selectivity decreases with increasing vigor of the reagent and up to 15% of the 3-isomer can be obtained. 2-Cyanothiophene is nitrated predominantly at position 4. 

The transformation of chlorophenols upon irradiation of nitrate mainly yields hydroxylated derivatives, while no nitration was observed. The absence of nitro derivatives can be attributed to the electron-withdrawing character of the chlorine atoms, inhibiting nitration. Dihydroxybenzenes and benzoquinone were also observed implying that a dechlorination process, induced by either hydroxyl or light, takes place in the system [123]. 

Indazoles are nitrated, mainly into the position 5 by a mixture of sulfuric and nitric acids or just by nitric acid (Scheme 2.1) with formation of 5-nitroindazole derivatives that are a part of so-called universal nucleosides [9],... 

Fusible explosives Mixtures of nitro compounds Mixtures with ammonium nitrate Manufacture and selection of fusible mixtures The flegmatizaiion of fusible mixtures Semi-fusible and infusible explosives Mixtures with nitrates — mainly with ammonium nitrate Mixtures with aluminium and other metak The preparation of S-iypc mixtures Mixtures with chlorates and perchlorates Mixtures with potassium and sodium chlorates Mixtures with potassium and ammonium perchlorates Plastic explosives... 

Further purification and characterization of the nitrated derivatives are in progress. However, preliminary pulse radiolysis experiments were carried out on the reaction mixtures nitrated mainly at peptide 227-243. Both CO2 " and Cd" were used as reductants to generate N02 -TyrCCP in situ. On pulsing solutions containing native CCP(Fe ), formation of CCP(Fe ) was observed at 438 nm and bimolecular rate constants of 2 X 10 s were observed... 

Reactions of dibenzopyridines show analogies with pyridine, quinoline and isoquinoline. Acridine and phenanthridine are A-protonated by strong protic acids, iV-alkylated by alkyl halides and A-oxidized by peroxy acids. Electrophilic substitutions of acridine often result in disubstitution at the 2- and 7-positions (e.g. nitration giving 3), whereas those of phenanthridine occur at different positions (e.g. nitration mainly at the 1- and 10-position yielding 4 and 5) ... 

These equilibria represent a more or less ideal case, since as a rule other substances are present, and also the nitro-amine which may be formed reacts farther. If sulfuric acid is present, a ternary intermediate compound would be formed. If acetanilide were used instead of aniline, the general reaction would be similar. If, however, a large excess of sulfuric acid were used in the reaction, then the aniline would be present practically entirely as aniline sulfate and there would not be the tautomeric form present. Under these circumstances, the intermediate compound would not be the same as before, and the nitration would proceed as if benzene itself were being nitrated. Mainly meta compound would be obtained under these conditions. The velocity of nitration of benzene derivatives containing different substituents was studied by H. Martinsen [Z. physik. Chem. 50, 385 (1905) 50, 605 (1907)1. He found the velocities to be dependent upon the substituents in the following way ... 

Alkyl nitrates, formed in a secondary channel of the reaction of RO2 with NO, are another "stable" form of NOy. LACTOZ has provided a comprehensive data set for the formation of nitrates, mainly from the higher molecular weight VOCs. In addition, the rates of degradation of organic nitrates, by photolysis and by their reaction with OH radicals, can be determined from LACTOZ results, although some uncertainties remain in the production and loss of alkyl nitrates. 

Modification of the mobile phase or the stationary phase leads to new methods or techniques. For instance, inclusion of silver ions from silver nitrate mainly in the stationary phase is used in argentation LC. This method enables a better separation of analytes containing one or more double bonds. The double bond forms a complex with the silver ion and this complex has greater retention, giving the possibility of differentiating the retention of compounds with double bond(s). Modification of the stationary phase with chiral compounds enables separation of the chiral compounds, which are of primary importance nowadays. This technique is called chiral separation. 

Since 2-pyridones are nitrated mainly as their free bases and are probably in the pyridone form, °° it is not likely that a transition state involving hydrogen-bond participation by OH as has been suggested for ortho-nitration of phenol and for nitration of 2-substituted-3-pyridinols at the 4-position (this section, p. 809) is responsible for the formation of 3-nitro-2-pyridone, the major product. ... 

Electrochemical reduction of the trithiapentalenes (804 R = H, Me, or Ph) yields the corresponding radical anions, which are converted into the thiapyran-thiones (807)/" ° 1-Phenyl-6,6a-dithia-l,2-diazapentalene (808) is nitrated mainly in position 3, but the 3,4-dimethyl derivative undergoes nitro-dediazoniation to the dithiole (809). Treatment of compound (808) with nitrous acid yields the phenylazo-oxadithiazapentalene (810) a similar reaction is the transformation of dioxathiapentalene (805) into the oxathiadiazapentalene (811) by the action of nitrobenzene-p-diazonium fluoroborate. ... 

Covalent reactivity. Nitration of the neutral species of aniline occurs in the ortho- and />ara-positions, whereas its cation becomes nitrated mainly in the m ta-position. Thus by changing the acidity of the nitration mixture, the proportions of the isomers can be controlled. An example of greater biochemical interest is ascorbic acid (lo./), which is readily oxidized by air when present as the di-anion, whereas the mono-anion and the molecule (either of which can be made the principal species present, by a change in pH) are quite stable (Weissberger and LuValle, 1944). 

Planted phytomass (seeds and roots) and irrigation water are two minor sources of nitrogen, the first one returning annually only about 2 Mt N, the second one contributing about twice as much. Nitrates (mainly from oxidation of NO released by combustion of fossil fuels) and volatilization of NHj (from animal wastes, soils, and plant tops) are the two largest sources of fixed atmospheric nitrogen, whose total annual deposition on the world s agricultural land is about 20 (18-22) Mt N. ... 

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