Esters of nitric acid

Various esters of nitric acid (HNO3) and polyvalent alcohols relax vascular smooth muscle, e.g., nitroglycerin (gly-ceryltrinitrate) and isosorbide dinitrate. The effect is more pronounced in venous chan in arterial beds. 

In general, the salts, esters, and halogen derivatives of nitric acid represent a poor compromise between performance and stability, and their future use in liquid systems appears limited. Several salts or esters of nitric acid have, however, achieved some prominence as oxidizers or monopropellants. The most important are the nitrates of alkali metals,... 

The use of nitroglycerine tablets has been known for several decades to dilate the blood vessels promptly thereby decreasing the blood pressure and thus giving instant relief from angina. However, the present trend is to use other esters of nitric acid such as erythritol tetranitrate, mannitol hexanitrate, PETN and other similar derivatives instead of NG for this purpose. These nitric acid esters being crystalline, are not assimilated readily and therefore, act more slowly but produce a longer lasting effect. 

Dynamit-Nobel AG, NethP, Appl 6411854 (1966) CA 65, 6992(1966) (Liquid esters of nitric acid and aromatic nitro compds can be gelatinized with polymers of unsatd acids or unsatd alcohols and their derivs. The advantages of these polymers include increased safety of manipulation and increased rate of gelatinizacioii. Thus a 60/40—NG/ NGc soin was mixed with 3 wt %-of finely powd polymethylacrylates and, after 1.5 hrs, had a viscosity of 4250 cp at 20° under shearing gradient of 15 sec )... 

Esters of nitric acid are characterized by the following atomic grouping ... 

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 ... 

Like nitrous esters, alkyl esters of nitric acid enter into reaction with a surplus of Grignard s reagent to form N-dialkylhydroxylamine. 

Later the relation between the decomposition of alkyl esters of nitric acid and the temperature was formulated (Will [78]) by means of the eqri. (64) ... 

The problem of producing asymmetric pentaerythritol tetranitrate esters of nitric acid, i.e. mixed pentaerythritol esters and pentaerythritol ether esters, is tackled from time to time in investigations which have the dual aims ... 

Wyler [54] suggested to producing mixed esters of nitric acid and of an organic acid also containing a hydroxylic group which would also be esterified by the nitric acid (a similar ester (V) was described above). This method has been applied by Wyler to obtain (nitrate-lactoyl)-pentaerythritol trinitrate, i.e. (a-nitroxypropionyl-pentaerythritol trinitrate) ... 

Discussion concerning aminoalcohol esters of nitric acid which are also salts of nitric acid, is developed further in the chapter devoted to nitric salts (see p. 472). 

The most important of the carbohydrate esters of nitric acid are the polysaccharide nitrates, particularly cellulose nitrate or nitrocellulose (NC) and starch nitrate ( nitrostarch ) which is much less used. Nitric esters prepared from other sugars such as saccharose and lactose are not of any importance as explosives. 

Pyridine and hydroxylamine separately exert only a weak influence on the highnitrated sugar esters of nitric acid, whereas when they are used together they bring about somewhat violent chemical reaction, as demonstrated by Hayward and Purves [21a],... 

These esters of nitric acid form one of the two groups of nitrates, the covalent group, which are also exemplified by nitryl hypofluorite and... 

Preparation 196.—Ethyl Nitrate (Ethyl-ester of nitric acid). 

A variety of solvents, monomers, medicines, perfumes, and explosives are made from esters of nitric acid. Ethyl acetate, //-butyl acetate, iso-butyl acetate, glycerol trinitrate, pentaerythritol tetranitrate (PETN), glycol dinitrate, and cellulose nitrate are examples of such reactions. 

Certain esters of nitric acid (cellulose nitrate, glyceryl trinitrate) are often referred to as nitro compounds (nitrocellulose, nitroglycerin), but this terminology should be avoided. 

As shown by T. Urbanski [143] between 1933 and 1937, there is a group of molecular addition compounds whose existence cannot be explained by all the points mentioned above. They are addition compounds of certain nitro compounds with esters of nitric acid. Thus many aromatic mononitro compounds form addition compounds with mannitol hexanitrate, and some aromatic trinitro compounds do so with erythritol tetranitrate (Vol. II). On the basis of these facts the author suggests that two main reasons are responsible for the formation of these addition compounds ... 

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). 

The organic nitrate nitroglycerin or glyceryl tri nitrate (GTN) a polyol ester of nitric acid was first synthesised in 1846 by Sobrero as an explosive and reported as a therapeutic agent in 1879 by Murrell for the relief and prophylaxis of angina pectoris. This was preceded by the use of the organic nitrite, amylnitrite, in 1857 for the treatment of angina and was the first described use of a nitrovasodilator. 

---