Nitrate esters alkaline nitration with

Alkaline nitration with alkoxide bases and nitrate esters was first explored by Endres and Wislicenus who synthesized phenylnitromethane by treating ethyl phenylacetate with potassium ethoxide in ethanol, followed by addition of ethyl nitrate and hydrolysis-decarboxylation of the resulting a-nitroester with aqueous acid. Phenylnitromethane is synthesized in a similar way via alkaline nitration of benzyl cyanide, followed by treatment of the resulting a -nitronitrile with aqueous base. ° Wieland and co-workers used alkali metal alkoxides and nitrate esters for the nitration of cyclic ketones but the yields and purity of product are often poor. ° ... 

Feuer and co-workers ° conducted extensive studies into alkaline nitration with nitrate esters, exploring the effect of base, time, stoichiometry, concentration, solvent, and temperature on yields and purity. Reactions are generally successful when the substrate a-proton acidity is in the 18-25 p A a range. Alkoxide bases derived from simple primary and secondary aliphatic alcohols are generally not considered compatible in reactions using alkyl nitrates. Optimum conditions for many of these reactions use potassium tert-butoxide and amyl nitrate in THF at —30 °C, although in many cases potassium amide in liquid ammonia at —33 °C works equally well. 

Nitric esters in alkaline medium. In some instances compounds containing an active methylene group can be nitrated with nitric esters in the presence of... 

Preparation. Coned, nitric acid (300 ml.) is chilled in ice and treated with cooling with 300 ml. of coned, sulfuric acid. In a second flask 150 ml. of methanol is cooled in ice to keep the temperature below 10° during cautious addition of 50 ml. of coned, sulfuric acid. One third of the cold nitric-sulfuric acid is placed in each of three 500-ral. Erlenmeyers, and each portion is treated with one third of the methanol-sulfuric acid mixture, added in 2-3 min. with constant swirling. Methyl nitrate separates as an almost colorless oily upper layer. After standing for 15 min. the lower layer of spent acid is separated and quenched with a large volume of water to avoid vigorous decomposition. The combined ester is washed with 25 ml. of ice-cold 22% sodium chloride solution, and the process is repeated with addition of enough alkali to produce a faintly alkaline reaction. The ester is washed free of alkali with ice-cold salt solution, then washed twice with 15 ml. of ice water, dried over calcium chloride, decanted, and used directly. Yield 190-230 g. (66-80%). Distillation is not recommended the crude ester is satisfactory for synthetic purposes. 

Feuer and co-workers also nitrated ring-substituted toluenes to the corresponding arylnitromethanes with potassium amide in liquid ammonia. Sulfonate esters and NJ -dialkylamides undergo similar nitration the latter isolated as their a-bromo derivatives. Alkaline nitration of ethyl and ferf-butyl carboxylic esters with potassium amide in liquid ammonia yields both the a-nitroester and the corresponding nitroalkane from decarboxylation. ... 

Acetone cyanohydrin nitrate, a reagent prepared from the nitration of acetone cyanohydrin with acetic anhydride-nitric acid, has been used for the alkaline nitration of alkyl-substituted malonate esters. In these reactions sodium hydride is used to form the carbanions of the malonate esters, which on reaction with acetone cyanohydrin nitrate form the corresponding nitromalonates. The use of a 100 % excess of sodium hydride in these reactions causes the nitromalonates to decompose by decarboxylation to the corresponding a-nitroesters. Alkyl-substituted acetoacetic acid esters behave in a similar way and have been used to synthesize a-nitroesters. Yields of a-nitroesters from both methods average 50-55 %. 

Electrophilic nitrations of aliphatic nitriles, carboxylic acids,carboxylic esters, ° and /3-diketones have been reported. The nitration of 2-alkyl-substituted indane-l,3-diones with nitric acid, followed by alkaline hydrolysis, is a standard laboratory route to primary nitroalkanes. ... 

Olah and co-workers reported the synthesis of 2,2,5,5-tetranitronorbornane (127) from 2,5-norbornadiene (122). In this synthesis formylation of (122) with formic acid yields the diformate ester (123), which on treatment with chrominm trioxide in acetone yields 2,5-norbomadione (124). Formation of the dioxime (125) from 2,5-norbornadione (124) is followed by direct oxidation to 2,5-dinitronorbomane (126) with peroxytriflnoroacetic acid generated in situ from the reaction of 90 % hydrogen peroxide with TFAA. Oxidative nitration of 2,5-dinitronorbornane (126) with sodium nitrite and potassium ferricyanide in alkaline solution generates 2,2,5,5-tetranitronorbornane (127) in excellent yield. 

Since in numerous cases of hydrolysis of nitric esters the presence of a large amount of nitrate ion has been established, which could be liberated only by rupture of the C—0 bond, the factors that influence the direction of this process should be discussed. Several investigations have thrown light on this problem, which is more complicated than with carboxylic esters, since during the hydrolysis of the latter compounds whether in acid or in alkaline medium only rupture of the ester bond can take place. This has been established in various ways including the use of water containing an 180-isotope. In general the hydrolysis of carboxylic esters can be defined by the equation ... 

Cordes and co-workers 191 found that the alkaline hydrolysis of p-nitrophenyl hexanoate is subject to catalysis by polyvinylpyridine-based polysoaps. For example, k bs is increased from 0.1 mm to 1.4 mm in the presence of 5 x 10 7 M 38% polysoap (23) (the same material used in the Strauss work). With 5 x 10-7 M polymer having a 15 % dodecyl content, the rate is increased only 3 times above background. The simplest rationale for the kinetics invokes both hydrophobic and electrostatic forces. Thus, dodecyl chains on the polymer hydrophobically bind p-nitrophenyl hexanoate to the polymer surface. Since the polymer possesses a high density of cationic nitrogens, hydroxide ions also accumulate at the polymer surface where they catalyze the hydrolysis of bound ester. Addition of nitrate ion to the aqueous reaction... 

An alternative route for the nitration of activated aromatic compounds, such as anisole, used a nitrate ester (RONO2) with triflic acid in an ionic liquid for ortho-selective nitration. Nitration in alkaline media can be accomplished with esters of nitric acid, such as ethyl nitrate (Et0N02). 

Alkaline hydrolysis of formate and halo-substituted acetic acid ester manufacture of cyclohexanone oxime manufacture of dithiocarbamate , alkylation of isobutane with butenes and of toluene and xylenes with acetaldehyde (or acetylene) nitration of toluene extraction of metals. 

In addition to DBP, ionizing radiation produces in TBP-hydrocarbon mixtures long-chain acid phosphate esters, nitrohydrocarbons, and nitrate esters that also complex uranium, plutonium, and zirconium, and that cannot be removed by simple alkaline washing. These must eventually be removed either by purging a fraction of the solvent or treating it with strong oxidants [B8]. 

TRICHL0R0-2-PYRID0L-0-ESTER WITH O,0-DIETYLPHOSPHOROTH-lOATE (2921-88-2) Incompatible with strong acids, antimony(V) pentafluoride, lead diacetate, magnesium, silver nitrate. Hydrolyzes from acid or alkaline solutions. 

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