Nitric Ester Groups

These have been determined in nitrocellulose by saponification, followed by reduction of the nitro group with Devada s alloy and determination of the ammonia produced [173]. 

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Mesylates and tosylates of isosorbide and isomannide undergo nucleophilic displacement with a number of primary and secondary amines, as described in a pharmaceutically oriented publication.131 Several patents describe the preparation of numerous aminodeoxyisohexide derivatives bearing an additional nitric ester group at the 2 or 5 position of the isohexide ring-system.142 144 207 Among these, purines and purine-alkylamines were... 

Monoketones containing additional exo or endo nitric ester groups have been synthesized.154 Starting from the appropriate nitrates 11 and 10, pyri-dinium chlorochromate as the oxidizing agent has been used for their preparation. The endo and the exo hydroxyl function were oxidized in comparable yield. The opposite reaction sequence, by nitration of the monoketones 8a and 8b, was also successfully employed (see Scheme 38). 

Nitrated cellulose acetate has been prepared, and nucleophilic replacement of nitrate groups of cellulose nitrate with halides has been performed. Oxidative decomposition of cellulose nitrate into a water-soluble material may be brought about by aqueous digestion at high temperature and high pressures, and this finds particular application in the determination of small proportions of the sulfate in cellulose nitrate. A route for the replacement of nitric ester groups in cellulose nitrate by sulfuric ester groups has been reported. ... 

Nitric ester groups Nitrocellulose Saponification, reduction with devades alloy determination of ammonia 204... 

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... 

Circular dichroism of the nitrato (ONO) chromophore of the mono- and di-nitric esters of l,4 3,6-dianhydrohexitols was found to consist of two dichroic bands, one weak and positive, at about 265 nm, and a stronger band at —228 nm, which was positive for the endo-(R)-nitrato chromophore and negative for the exo-(S)-nitrato group.68 However, for l,4 3,6-dianhydro-D-glucitol dinitrate, which has both an endo and an exo nitrato group, both bands were positive, but [ ]ma r (+ 7,260) for the band at 225 nm was about half of the algebraic sum of this band for the di-endo (+ 18,400) and di-exo (—4,460) compounds. 

Explosiveness and Constitution, According to Majrich, the explosiveness depends not only on the nature of the carbon chain, but alsd on other groups. For instance the aldehyde, Keto and carboxylic groups lower the brisance, sensitiveness and stability, especially in nitric esters and the stability seems to increase with increasing mol wt Ref A. Majrich, Chem Obzor 7, 104-8,... 

Nitramines differ from nitro compounds in possessing a somewhat better oxygen balance, due to the fact that the group N—N02 gives twice the volume of nitrogen as the group C—N02. On the other hand nitramines have a worse oxygen balance than nitric esters. 

CA 65, 568(1966) [Fluid nitric esters, nitro aromatic compds or their mixes can be thickened and made plastic by addn of soluble polymers that contain neither nitro nor perchloro groups. The gelled compds are useful in the manuf of expls and propints. Polymers used include poly(Me-methacrylate), poly(vinyl acetate), EtOAc-vinyl chloride, phenol-HCHO, poly-(vinylpyrrolidinone) and poly(vinylpyrrolidi-none)-poly(vlnylacetate)]... 

When an amide of a hydroxy aliphatic mono-carboxylic acid of the general formula HOCHj. CONRH(where R is an alkyl radical) is treated with nitric acid, nitric esters (OjNO. CHa. CO. NHR) are usually obtained. However, in some cases NO groups are also introduced yielding compds of the general formula O%N0. CHa. CO. N(NO,)R... 

The structure of the nitro group present in nitric esters is the same as that in nitro compounds. 

X-Ray investigations, electron diffraction, Raman and infra-red spectra, and dipole moment measurements of nitric esters also support the idea of a symmetrical structure for the nitrate group (in spite of certain discrepancies obtained by different authors) ... 

An extensive study was carried out by Brown [26] who examined over twenty esters of nitric acid and found the characteristic stretching frequencies of the N02 ester group ... 

There are various different methods for reducing nitric esters and thereby removing their nitro group. In most cases the original alcohols are recovered as result of the reaction. 

In the presence of sodium or potassium ethoxide, nitric esters react with substances containing an active methylene group to form salts of aci-nitro compounds (Wislicenus [64]) as quoted above in eqn. (59). Esters are hydrolysed on this occasion. 

An interesting exception reported by Rogovin and Tsaplina concerns vinyl acetate which when exposed to the influence of nitric esters, polymerizes very slowly. The ester radicals -N02, -ONC>2 and ions NO , ONO , do not seem to influence appreciably the rate of polymerization and the catalytic action of nitric esters is not produced by the presence of O—N02 groups. 

According to Hess, Trogus and Tomonari [8] mixed sulphuric and nitric esters of cellulose are soluble in methyl alcohol. Hence by boiling nitrocellulose in methyl alcohol it is possible to remove these substances up to a quantity corresponding to some 1% of the nitrocellulose mass. The extracted product contains three N02 and two S03H groups for every two C6H10O5 units. 

It has been found that even in the presence of a small number of carboxyl groups an appreciable change in the properties of the nitric ester is brought about, as compared with nitrocellulose. 

These figures show that the nitric ester is scarcely soluble in a good solvent for nitrocellulose such as acetone when it contains 2 or 3% of COOH groups, i.e. one carboxylic group for 8-10 pyran rings. 

The sugars are polyhydric alcohols which contain an aldehyde or a ketone group or a cyclic acetal or ketal arrangement within the molecule. They yield nitric esters which are perhaps less stable than the nitric esters of the simple polyhydric alcohols but which probably owe part of their reputation for instability to the... 

Epoxides 72 may also act as starting materials for hybrid structures 77 containing an isohexide and a glyceryl moiety, with nitric ester functions at different positions.172 Additional monoethers of isosorbide 2- and 5-nitrate 78 were synthesized by reaction of the free hydroxyl group with any of several alkyl iodides in the presence of freshly prepared silver oxide. The yields were low, as usual.146 Amongst a larger series of different alcohol... 

Because of the known vasodilating activity of isohexide nitric esters, several attempts were made to improve or modify these compounds by introducing additional substituents at the second hydroxyl group. On the one hand, this type of molecular modification would influence the polarity and... 

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