Ethyl nitrite, reaction

There is a way around the hasslesome purification procedure that will allow the underground chemist to use the ethyl nitrite he has made quickly and easily. The way to do this is to bubble the vapors of the ethyl nitrite into the reaction mixture. This method avoids the unpleasant and possibly dangerous procedure with the sep funnel and subsequent distillation. See Figure 8 back in Chapter 4 on N-methyl formamide. If in that figure, the methylamine containing flask instead contained the ethyl nitrite reaction mixture, and the formic acid containing flask instead had the allylbenzene and palladium chloride in alcohol needed for phenylacetone production, then one could easily picture how to get the ethyl nitrite vapors to directly bubble into the phenylacetone production mix without any need to manipulate the nitrite directly. 

Caryophyllene nitrosochloride, (CjgHgJjN OoCL, is obtained when a mixture of the sesquiterpene, alcohol, ethyl acetate, and ethyl nitrite is cooled in a freezing mixture, and then treated with a saturated solution of hydrochloric acid in alcohol. The reaction mass is allowed to stand on ice for an hour and is then exposed to sunlight. Thus prepared it melts at about 158° to 163°, and can be separated into two compounds, one being that of a-caryophyllene and the other that of yS-caryophyllene Deussen s sesquiterpenes of natural caryophyllene from clove oil), a-caryophyllene nitrosochloride melts at 177", and /3-caryophyllene nitrosochloride at 159°. They can be separated by fractional crystallisation. The corresponding a-nitrolbenzylamine melts at 126° to 128°, and the /3-nitrolbenzylamine at 172° to 173°. The bimolecular formula given above is probable but not certain. 

Terpineol nitrosochloride, Cj Hj-OH. NOCl, is, perhaps, the most suitable derivative to prepare for the identification of terpineol. To a solution of 15 grams of terpineol in 15 c.c. of glacial acetic acid, 11 c.c. of ethyl nitrite are added. The mixture is cooled in ice, and 6 c.c. of hydrochloric acid mixed with 6 c.c. of glacial acetic acid are added drop by drop, with continual shaking. Care must be taken to avoid a rise in temperature. When the reaction is compdete, water is added to pjre-cipitate the nitrosochloride. The oily liquid soon solidifies and may be recrystallised from boiling acetic ether or from methyl alcohol. Ter-... 

When all the ethyl nitrite has been added, the reaction mixture is refluxed for approximately one hour, then concentrated to dryness under reduced pressure (25 to 30 mm Hg) and at a maximum temperature of 70°C. The crystalline residue is dissolved in 35 liters of water and adjusted to a pH of 8 to 9 by addition (with cooling and stirring) of 11 to 12 kg of caustic soda. The sodium chloride formed is filtered off, and the filter cake is washed with 20 liters of normal butyl alcohol. This wash liquid is used for the first extraction of the product from the aqueous filtrate. The filtrate is then further extracted with four successive 20-liter portions of n-butyl alcohol. 

The diazotization reaction can also be initiated via the vapor phase, e. g. with ethyl nitrite that can be generated in one trough of a twin-trough chamber by adding a few drops of cone, hydrochloric acid to a mixture of ethanol and saturated aqueous sodium nitrite solution (1 + 1) [3] the less volatile amyl nitrite can be used as an alternative [3]. 

A kinetic study of the previously reported substitution of aromatic nitro groups by tervalent phosphorus has established an aromatic 5n2 mechanism. Similarities in values of activation energies, and in relative reactivities of phosphite and phosphonite esters, between this displacement and the Arbusov reaction suggest a related mechanism (31), while the lack of reactivity of p-dinitrobenzene is attributed to the need for intramolecular solvation (32). The exclusive formation of ethyl nitrite, rather than other isomers, is confirmed from the decomposition of triethoxy-(ethyl)phosphonium fluoroborate (33) in the presence of silver nitrite. A mechanism involving quinquevalent phosphorus (34) still seems applicable, particularly in view of the recent mechanistic work on the Arbusov reaction. ... 

The kinetics of the various reactions have been explored in detail using large-volume chambers that can be used to simulate reactions in the troposphere. They have frequently used hydroxyl radicals formed by photolysis of methyl (or ethyl) nitrite, with the addition of NO to inhibit photolysis of NO2. This would result in the formation of 0( P) atoms, and subsequent reaction with Oj would produce ozone, and hence NO3 radicals from NOj. Nitrate radicals are produced by the thermal decomposition of NjOj, and in experiments with O3, a scavenger for hydroxyl radicals is added. Details of the different experimental procedures for the measurement of absolute and relative rates have been summarized, and attention drawn to the often considerable spread of values for experiments carried out at room temperature (-298 K) (Atkinson 1986). It should be emphasized that in the real troposphere, both the rates—and possibly the products—of transformation will be determined by seasonal differences both in temperature and the intensity of solar radiation. These are determined both by latitude and altitude. 

Because ethyl nitrite is harmful if inhaled continuously, the reaction should be carried out in a hood or out of doors. 

Condensations with alkyl nitrites and nitrates, however, are not so generally applicable as the true ethyl acetoacetate reaction, and the possibility is not excluded that they proceed in another way compounds with mobile hydrogen might first he added to the inorganic part of the ester by means of an aldol condensation. The fact that fluorene, which contains no active double bond at all, combines with ethyl nitrate (as well as with ethyl oxalate) and sodium ethoxide in the same way, yielding oci-nitrofluorene, seems to support this second theory (W. Wislicenus). 

Nitroethane. 42 g of dry silver nitrite is placed in a flask fitted with a reflux condenser. Note To recover the by-product (ethyl nitrite) ice water must be used in the condenser, which needs to be a long one. Gradually add 34 g of ethyl iodide, so that the mixture does not boil too violently (it should boil vigorously). Do not shake or disturb the flask during this procedure. After the addition, reaction has subsided, warm the flask for 2 hours on a water bath, cool well, and fractionally distill after rigging the apparatus to do so. Ethyl nitrite distills over at 68° and is collected in a below freezing mixture. Nitroethane distills over at 110-114° and must be redistilled once more. Yield 8-9 g. 

A mechanistically intriguing transformation resulted when 9-aminocarbazole formed salt 137 via the reaction of its Grignard derivative with dibromo-triphenylphosphorane. Reaction of the salt 137 with ethyl nitrite gave 3-bromocarbazole the authors speculate that nitrosation followed by nitrogen loss generates the carbazol-9-yl cation, attacked in a nucleophilic sense by bromide at C-3. ... 

All this was purely physical action and no chemical reaction took place and no gas evolved, unless alcohol had been used. When alcohol was used, as in shellac for the booster cavity or for washing the threads, in the nose of the shell, some chemical reaction took place and not only exudate was formed but gas as well- This gas has proved to be Ethyl Nitrite. By laboratory experiments, it was determined that TNT and alcohol do react and give the same gas and tarry mater ial as that found in the shells... 

In an apparatus suitably protected against atmospheric moisture and fitted with a gas-inlet tube, mechanical stirrer, and an efficient reflux condenser, to a solution of 45 gm (0.45 mole) of ethyl isopropyl ketone and 5 gm of freshly distilled acetyl chloride is added, through the gas-inlet tube, 18 gm (0.24 mole) of ethyl nitrite at 45°-55°C over a 2 hr period. The reaction mixture is stored overnight in a refrigerator, whereupon 15.2 gm (48.7% based on ethyl nitrite used) of 2-methyl-2-nitroso-3-pentanone dimer (bimolecular ethyl a-nitroso-isopropyl ketone) deposits. The product is isolated by filtration, m.p. 122°-123°C. 

This reaction gives the volatile by-products ethyl nitrate, ethyl nitrite and acetic acid, NO, N02 and C02. 

Reaction (6) is particularly well suited for use in the preparation of the organic derivatives of hydrazoic acid from the corresponding derivatives of hydrazine. Nitrous esters may be employed, instead of the acid, e.g. ethyl nitrite in the presence of sodium hydroxide... 

Selective oxidation of polymethylpyrimidines. 2,4-Di- and 2,4,6-trimethyl-pyrimidines are selectively oxidized to 4-carboxylic acids by a slight excess of Se02 in pyridine. Yields are about 40-65%. This increased reactivity of a 4-methyl group of polymethylpyrimidines is also observed in reaction with ethyl nitrite in liquid ammonia to form 4-aldoximcs and with ethyl benzoate in the presence of KOC2H to form phenacyl derivatives. 

The NO -ion might be formed from the nitrous acid ester if the latter was present as an impurity in the main reactant. Trials carried out with ethyl nitrite and n-butyl nitrite have demonstrated, however, that when these compounds are treated with an excess of hydrazine they do not undergo any chemical reaction accompanied by the formation of the nitrate ion. 

Hydrazoic acid is formed (I) by reaction of sodium nitrate with molten sodamide, (2) by reaction of nitrous oxide with molten sodamide, (3) by reaction of nitrous acid and hydrazinium ion (N2H51), (4) by oxidation of hydraz.mium sails. (5) by reaction of ethyl nitrite with NaOH solution and acidifying. See also Azides... 

The commercial preparation of mercury fulminate is carried out by a process which is essentially the same as that which Howmrd originally recommended. Five hundred or 600 grams of mercury is used for each batch, the operation is practically on the laboratory scale, and several batches are run at the same time. Since the reaction produces considerable frothing, capacious glass balloons are used. The fumes, which are poisonous and inflammable, are passed through condensers, and the condensate, which contains alcohol, acetaldehyde, ethyl nitrate, and ethyl nitrite, is utilized by mixing it with the alcohol for the next batch. 

Ethyl nitrite may be prepared by dissolving 38 g (0.55 mol) of sodium nitrite in 120 ml of water in a 500-ml flask equipped as above. Dilute 23 g (29 ml, 0.5 mol) of ethanol with an equal volume of water, carefully add 25 g (13.5 ml) of concentrated sulphuric acid and dilute to 120 ml with water. Cool both solutions to —10 °C in an ice-salt bath and add the acid-alcohol mixture to the nitrite solution slowly with constant stirring during about 30 minutes. Transfer the reaction mixture to a cooled separating funnel, run off- the lower aqueous phase, wash the ethyl nitrite layer rapidly with ice-cold 2 per cent sodium hydrogen carbonate solution and dry over anhydrous sodium sulphate. The product may be kept at 0°C as a 50 per cent solution in absolute ethanol if required but should be used as soon as possible. The b.p. of pure ethyl nitrite is 17 °C. 

In addition to short-lived molecules that were assigned to the structure classes discussed above, there are various interesting intermediates that are mentioned here separately. Nitrosomethane (38), which is the less stable tautomer of formaldoxime, was generated by collisional reduction of the stable cation-radical and characterized by NRMS [155,156]. The precursor cation for 38 was produced by three different reactions, e.g., elimination of OH upon exothermic protonation of nitromethane [156], electron-induced loss of O from nitromethane [155, 156], and electron-induced CH20 extrusion from ethyl nitrite [156] (Scheme 15). Nitrosomethane gives rise to a moderately abundant survivor ion in the +NR+ mass spectrum and does not undergo unimolecular isomerization to any of its more stable tautomers. 

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