Nitric acid esters, hydrolysis

E. Schulek et al, Hydrolysis of Nitric Acid Esters (Nitro Compounds) ,... 

The reactivity of nitric acid esters and in particular the complicated chemical composition of the products formed by their hydrolysis led some investigators [1, 37] to express the view that nitric esters may have the structure of peroxy-compounds (I) ... 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Bromobenzaldehyde has been prepared by the oxidation of -bromotoluene with chromyl chloride/ by saponification of the acetal from />-bromophenylmagnesium bromide and orthoformic ester/ by the oxidation of ethyl -bromobenzyl ether with nitric acid/ by the oxidation of /j-bromobenzyl bromide with lead nitrate/ and by the hydrolysis of i-bromobenzal bromide in the presence of calcium carbonate. ... 

The ester group is then hydrolysed, and the hydrolysis normally stops at the MePO(OH)2 stage. More vigorous conditions are required to rupture the Me—P bond. Thus the normal hydrolysis product of D.F.P. and of tabun, namely, phosphoric acid, will give a positive test with ammonium molybdate, whereas the product from sarin, namely, methylphosphonic acid, will not respond to this test. Vigorous reagents such as hot nitric acid and ammonium persulphate will break the C—P link and then a positive test for phosphate is obtained with ammonium molybdate. Sarin can be prepared in a variety of ways. Three... 

These compounds contain the fragment R as an alkyl or aryl moiety. In other words, they result from the esterification of an alcohol or a phenol with nitrous acid, nitric acid, phosphoric acid, sulfuric acid, or sulfamic acid, respectively. Many of the esters to be examined in this chapter must be activated prior to eliciting their effects, e.g., the organic nitrites and nitrates, which act as donors of nitric oxide or an analogous molecule, and phosphates, which are activated by hydrolysis or even by phosphorylation (antiviral agents). Sulfates are very seldom active or used as prodrugs, but they have significance as metabolites and as industrial xenobiotics. 

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. ... 

Treatment of DPT (239) with dinitrogen pentoxide in pure nitric acid leads to the isolation of the nitrate ester (249), an unstable explosive which is highly sensitive to impact and readily undergoes hydrolysis. A low nitration temperature favours the formation of (249) and its presence during the nitrolysis of hexamine is clearly undesirable. The nitrolysis of DPT (239) with one equivalent of pure nitric acid in an excess of acetic anhydride yields 1-acetomethyl-3,5,7-trinitro-l,3,5,7-tetraazacyclooctane (251), a useful starting material for the synthesis of other explosives. ... 

Bomeol is oxidized to camphor with chromic or nitric acid dehydration with dilute acids yields camphene. Bomeol is readily esterified with acids, but on an industrial scale bornyl esters are prepared by other routes. For example, levorotatory bomeol is synthesized industrially from levorotatory pinenes by Wagner Meerwein rearrangement with dilute acid, followed by hydrolysis of the resulting esters [86]. 

In the investigation with n-butyl nitrate by Merrow, van Dolah and Cristol [41] already cited, neither the presence of the nitrate ion nor of mercaptan was detected. For this reason the following reaction mechanism was proposed for the hydrolysis of nitric acid alcohol esters by means of hydrosulphide ... 

The oldest and most popular method is reductive hydrolysis by means of alkaline sulphides or hydrosulphides, for instance sodium or ammonium sulphide or the corresponding hydrosulphide, as discussed above in connection with the question of hydrolysis (pp. 9-10). According to Oehman et al. [103] acid hydrolysis of nitroglycerine follows a course similar to that of eqn. (58). Hydrolysis with sulphuric acid (even in the presence of nitric acid) may lead to a transesterification and formation of sulphuric acid esters [104]. 

The simplest and most commonly used method of preparing nitric esters consists in the O-nitration reaction of alcohols with nitric acid, usually in the presence of sulphuric acid. The reaction is accompanied by reversible hydrolysis, which is typical of esterification reactions. It is very likely that the main nitrating agent is the nitronium ion NO (nitryl cation). It acts through electrophilic substitution. The presence of sulphuric and perchloric acids in the esterifying mixed acid favours the esterification, as it increases the concentration of NO ion. 

Adipic acid has been prepared by the following methods the action of silver1 or copper 2 on /3-iodopropionic acid the reduction of mucic add with phosphorus and iodine 3 the electrolysis of the potassium or sodium salts of monoethyl succinate 4 the condensation of ethylene chloride or bromide with malonic ester or cyanoacetic ester and subsequent hydrolysis 5 the oxidation of certain fractions of Baku petroleum 6 the oxidation of cyclohexanol or cyclohexanone with nitric acid 7 or potassium permanganate.8... 

Many methods have been mentioned in the literature for the preparation of glutaric acid. Of these, the only methods of preparative interest are the hydrolysis of trimethylene cyanide with acids or alkalies,1 the hydrolysis of methylene dimalonic ester2 or methylene dicyanoacetic ester,3 and the oxidation of cyclopentanone with nitric acid.4 In this country the cheapness of trimethylene glycol makes it the best source for glutaric acid. The method described in the procedure is a modification of that originally described by Reboul.5... 

Use of sensors to measure gas phase NO2 concentration, electrical conductivity of the reaction mass, and gas phase temperatures at several critical points in semi-continuous nitration reactors permits safe operation of nitration processes [10]. The use of non-aqueous titration analysis in the control of nitration processes in explosives manufacture is discussed [11]. Counter-intuitively, safety of spent acids from nitrate ester production is decreased by lowered nitric acid content. This is because the runaway reaction is oxidation of alcohols, kinetically easier than that of the dissolved nitrate esters from which the alcohols are reformed by hydrolysis [16]. 

Dinitropyrocatechol (m. p. 164°C) was prepared by Nietzki and Moll [38] by nitrating pyrocatechol diacetate with cold cont. nitric acid, followed by hydrolysis of ester groups with sulphuric acid. 

To make rosoxacin two heterocyclic systems must be constructed. Workers at the pharmaceutical company Sterling decided to build the pyridine in an ingenious version of the Hantzsch synthesis using acetylenic esters on 3-nitrobenzaldehyde. The ammonia was added as ammonium acetate. Oxidation with nitric acid made the pyridine, hydrolysis of the esters and decarboxylation removed the acid groups, and reduction with Fe(TT) and HC1 converted the nitro group into the amino group required for the quinolone synthesis. 

The mixture of the (R)-HMPC and the (S)-acetate 4 from the enzymatic hydrolysis was esterified with methanesulfonyl choride and triethylamine to afford a mixture of the corresponding (R)-sulfonate 5a and the (S)-acetate 4. The (S)-acetate 4 was unaffected by the sulfonation conditions. The resultant mixture of two esters, 4 and 5a, was hydrolyzed in the presence of a small amount of calcium carbonate. The (R)-sulfonate 5a was converted into the (S)-HMPC 6 as a result of inversion of configuration. On the other hand, the (S)-acetate 4, was hydrolyzed with retention of configuration. Consequently, all of the racemic acetate J3, was converted with maximum efficiency to the desired (S)-HMPC 6, by the sequence enzymatic hydrolysis and sulfonation followed by inversion of the chiral center in (R)-HMPC without separation of the (S)-acetate Similar transformations could also be carried out via nitrate ester intermediate 5b obtained from the reaction of the (R)-HMPC with nitric acid and acetic anhydride. 

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