Nitration of the parent alcohol

2 NITRATION OF THE PARENT ALCOHOL 3.2.1 0-Nitration with nitric acid and its mixtures 

The direct action of nitric acid and its mixtures on the parent alcohol is by far the most important method for the production of nitrate esters on both an industrial and laboratory scale. While such reactions are essentially esterifications they are commonly referred to as 6 -nitrations because the reaction mechanism, involving substitution of hydrogen for a nitro group, is not dissimilar to other nitrations and frequently involves the same nitrating species. 

While nitric acid is a good solvent for many organic substrates, sulfuric acid is not, and its presence often reduces the solubility of polyols in the mixed acid, leading to heterogeneous suspensions. This is the case for many solid polyols, particularly sugars which form heterogeneous pastey masses on addition to mixed acid. This has meant, for some substrates, nitric acid is 

Commercial 70 % nitric acid can be used for the 6 -nitration of low molecular weight alcohols like ethanol and 2-propanol. The nitrate ester products are isolated from the cautious distillation of a mixture of the alcohol and excess 70 % nitric acid. The presence of urea in these reactions is very important for the destruction of nitrous acid and its omission can lead to very violent fume-off. However, this method is not recommended on safety grounds. Using temperatures above ambient for the O-nitration of alcohols, with either nitric acid or mixed acid, is dangerous and greatly increases the risk of explosion. 

More obscure reagents used for 0-nitration include mixtures of phosphoric and nitric acids, and anhydrous nitric acid in which phosphorous pentoxide has been dissolved. The latter mixture contains dissolved dinitrogen pentoxide and is a powerful nitrating agent. A mixture of anhydrous nitric acid containing catalytic amounts of boron trifluoride has been reported to lead to the rapid 0-nitration of alcohols.  

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The Henry condensation of nitroform and terminal dinitromethyl compounds with formaldehyde and other aldehydes, followed by nitration of the resulting alcohol functionality, has been used to synthesize numerous explosives. The nitrate esters (104), (105), (106) " and (107)155 ij yg ijggjj synthesized from the action of absolute nitric acid on the parent alcohols. In a similar manner, NMHP (109) is synthesized from the condensation of TNHP (108) with formaldehyde, followed by O-nitration with absolute nitric acid. ... 

The postexplosion analysis of some nitrate esters, mainly PETN and NG, is further complicated by the presence of hydrolysis products, which are lower nitrate esters of the parent alcohol [67,69,70]. Figure 6 shows the structural formulas of the hydrolysis products of PETN. These compounds appear also in thin-layer chromatography (TEC) [69] and LC-MS [71] of extracts containing PETN and NG. If unaware of their presence, they may lead to erroneous interpretation of the GC-MS results. As the lower nitrate esters have free hydroxyl groups, conversion to trimethylsilyl (TMS) derivatives was carried out prior to the GC-MS analysis [67]. In an actual case, the TLC analysis revealed several Griess-... 

However, styrene and cyclohexene gave complex product mixtures, and 1-octene did not react under the same reaction conditions. Thus, the activity of this catalyst is intrinsically low. Jacobs and co-workers [159,160] applied Veturello s catalyst [PO WCKOj ]3- (tethered on a commercial nitrate-form resin with alkylammonium cations) to the epoxidation of allylic alcohols and terpenes. The regio- and diastereoselectivity of the parent homogeneous catalysts were preserved in the supported catalyst. For bulky alkenes, the reactivity of the POM catalyst was superior to that of Ti-based catalysts with large pore sizes such as Ti-p and Ti-MCM-48. The catalytic activity of the recycled catalyst was completely maintained after several cycles and the filtrate was catalytically inactive, indicating that the observed catalysis is truly heterogeneous in nature. 

Solutions of dinitrogen pentoxide in anhydrous nitric acid are unlikely to find wide use for the industrial synthesis of nitrate esters - synthesis from the parent alcohol is relatively straightforward and so this reagent, which is more expensive than mixed acid, holds few advantages. 

Cyclic ethers are oxidized to lactones in the presence of cerium(IV) salts. Treatment of tetrahydiofu-ran with cerium(rV) ammonium nitrate in the presence of primary, secondary or tertiary alcdiols leads to the formation of the corresponding tetrahydrofuranyl ethers in quantitative yield. Fuitfaermoie, 4-meth-oxybenzyl ether derivatives of carbohytbates are selectively deprotected to the parent alcohols on reaction with cerium(IV) ammonium nitrate in aqueous acetonitrile. ... 

From many possible precursors [e.g., metal nitrates or acetates (12), mono-dispersed metal hydrous oxides (549), oxides dissolved in alcohols (12), oxo-alkoxides (550), and alkoxides (12)], metal alkoxides were considered as specially suitable precursors (12, 31, 551) for the preparation of oxide ceramics since the 1950s, mainly due to the ease of their purification. This purification was generally distillation and in some cases crystallization, for example, Zr(0-i-Pr)4(i-Pr-OH), solubility in organic solvents such as the parent alcohols that are miscible with water, and their extremely facile hydrolyzability, which can be modulated effectively by substitution of some of the alkoxide groups with chelating ligands such as (3-diketonates (35, 536). The extraordinary future potential and possibilities of the SG process were reemphasized recently by Sakka (534) and Roy (552) in two review articles. 

Oximes and semicarbazones are oxidized by ceric ammonium nitrate to the parent carbonyl compound in yields of 70-80%. Aqueous alcohols, acetonitrile, and acetic acid are suitable solvents, and the reaction is rapid at 0°.7... 

Anionics. The analysis of LAS using a Silica Gel G layer (a standard TLC silica) impregnated with 10% ammonium sulphate, with 2-methyl-4-pentanone/propyl alcohol/0.1 N acetic acid/acetonitrile (20 6 1.6 1, v/v/v/v) and visualisation by a spray of 5% phosphomolybdic acid in ethanol followed by charring by heating is described in [41]. The analysis of the parent LAB using layers of silica gel impregnated with 15% silver nitrate and double development with dichloromethane followed by recovery of the spots and analysis by GC/MS is described in [2]. 

Trinitrophenoxyethyl alcohol, the parent substance of trinitrophenoxyethyl nitrate, was also obtained by Wasmer [89] in another way, namely ... 

Like the double bond, the carbon-carbon triple bond is susceptible to many of the common addition reactions. In some cases, such as reduction, hydroboration and acid-catalyzed hydration, it is even more reactive. A very efficient method for the protection of the triple bond is found in the alkynedicobalt hexacarbonyl complexes (.e.g. 117 and 118), readily formed by the reaction of the respective alkyne with dicobalt octacarbonyl. In eneynes this complexation is specific for the triple bond. The remaining alkenes can be reduced with diimide or borane as is illustrated for the ethynylation product (116) of 5-dehydro androsterone in Scheme 107. Alkynic alkenes and alcohols complexed in this way show an increased structural stability. This has been used for the construction of a variety of substituted alkynic compounds uncontaminated by allenic isomers (Scheme 107) and in syntheses of insect pheromones. From the protecting cobalt clusters, the parent alkynes can easily be regenerated by treatment with iron(III) nitrate, ammonium cerium nitrate or trimethylamine A -oxide. ° ... 

The rate data for reaction of NO3 with aliphatic esters show that the presence of the ester group in an organic molecule has little influence on the reactivity compared to the parent alkane. The reactivity trends exhibited by the nitrate radical for reactions with alcohols, ethers and esters are similar to those shown for the analogous reactions of hydroxyl radicals. The major products identified from the NO3 radical-initiated oxidation of alcohols, ethers and esters under atmospheric conditions were esters, carbonyls and alkyl nitrates. Similar products arise from the reactions of OH radicals with these molecules under atmospheric conditions. 

The first application, conceived by Schonbein, was gun cotton, which, indeed, he showed off at the Woolwich Arsenal in London he even presented a brace of pheasants—the very first to fall to shot propelled by gun cotton— to Prince Albert. But a much more important discovery soon followed, namely that a less extensively nitrated cellulose, which became known as pyroxylin, could be dissolved in a variety of organic solvents (in which the parent cellulose was wholly insoluble). The viscous solution of pyroxylin, commonly in a mixed solvent of ethanol (drinking alcohol) and ether, was called collodion. This would dry when painted on a surface to form a tough colourless film. It quickly found its first serious application, in photography, as... 

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