Nitrous acid ethyl ester

V-Nitrosopyrrolidine. Pyrrolidine, 1-nitroso- (8,9) (930-55-2) Ethyl nitrite Nitrous acid, ethyl ester (8,9) (109-95-5)... 

NITROUS ACID ETHYL ESTER (109-95-5) Thermally unstable. Heat around or above 190°F/88°C can cause explosive decomposition (may not need air or oxygen). Decomposes in air, sunlight, or moisture. Forms explosive mixture with air (flash point —31°F/—35°C). A powerful oxidizer. Violent reaction with acids, acid fumes, amines, ammonia, cyanides, reducing agents, other strong oxidizers, salts. 

UN 1194 (DOT) FEMA 2446 Synonyms Nitrosyl ethoxide Nitrous acid ethyl ester Nitrous ether Nitrous ethyl ether Spirit of ethyl nitrite... 

Nitrous acid, calcium salt. See Calcium nitrite Nitrous acid ethyl ester. See Ethyl nitrite Nitrous acid, isobutyl ester. See Isobutyl nitrite Nitrous acid, isopentyl ester Nitrous acid, 3-methylbutyl ester. Seejsoamyl nitrite Nitrous acid, 2-methylpropyl ester. See Isobutyl nitrite... 

Ethyl nitrite Nitrous acid, ethyl ester X ... 

The diazotization of heteroaromatic amines is basically analogous to that of aromatic amines. Among the five-membered systems the amino-azoles (pyrroles, diazoles, triazoles, tetrazoles, oxazoles, isooxazoles, thia-, selena-, and dithiazoles) have all been diazotized. In general, diazotization in dilute mineral acid is possible, but diazotization in concentrated sulfuric acid (nitrosylsulfuric acid, see Sec. 2.2) or in organic solvents using an ester of nitrous acid (ethyl or isopentyl nitrite) is often preferable. Amino derivatives of aromatic heterocycles without ring nitrogen (furan and thiophene) can also be diazotized. 

In the present preparation, ethyl acetoacetate is treated with sufficient nitrous acid to convert half into the a-nitroso (or a-oximino) ester, which is reduced by zinc and acetic acid to the a-amino ester (I). The latter then condenses with... 

CH3.(CH2)2.C(C02.C2H5XC0.N3) mw 198.23 N 21.20% OB to C02 -153.36% ypl oil, expl. Sol in eth and CC14. Prepn is by reacting the K salt, of the half (or mono) ethyl ester of propyl malonic acid with nitrous acid Refs 1) Beil, not found 2) T. Curtius W, Lehmann, Transformation of alkylated malonic acids into a-amino acids. III. Synthesis of cr-aminovaleric acid, propylmalonylazidic acid. . JPraktChem 125, 211-302 (1930) CA 24, 3215(1930)... 

The esters of nitrous acid are characterised by their high velocities of formation and hydrolysis. They are almost instantaneously decomposed by mineral acids and in the method of preparation given this has been taken into account. The slightest excess of hydrochloric acid must be avoided. Advantage is taken of this property of the alkyl nitrites in all cases where it is desired to liberate nitrous acid in organic solvents (in which metallic nitrites are insoluble). Examples addition of N203 to olefines, preparation of solid diazonium salts (p. 286), production of isonitroso-derivatives from ketones by the action of HN02. This synthesis is often also carried out in the manner of the acetoacetic ester synthesis, with ketone, alkyl nitrite, and sodium ethylate the sodium salt of the isonitrosoketone is formed (cf. in this connexion p. 259) ... 

Isocarboxazid Isocarboxazid, 2-benzylhydrazid-5-methyl-3-isoxazolecarboxylate (7.2.6), can be synthesized from acetylacetone, which on nitrosation with nitrous acid gives 5-methyl-isoxazol-3-carboxyhc acid (7.2.2). Esterification of this product gives the ethyl ester of 5-methyl-isoxazol-3-carboxyhc acid (7.2.3). The synthesized ester (7.2.3) is further reacted with benzylhydrazine, to give isocarboxazide (7.2.6), or with hydrazine, which forms 5-methyl-isoxazol-3-carboxylic acid hydrazide (7.2.4). Reacting the latter with benzaldehyde gives hydrazone (7.2.5), which is further reduced to the isocarboxazide (7.2.6) [46,47]. 

According to Fanner [38] the first stage of hydrolysis proceeds in accordance with the eqn. (1) (p. 7). Afterwards, the products react with one another to form nitrous acid or nitrites and the series of compounds ennumerated above. Fanner s hypothesis seems unsatisfactory when hydrolysis of nitric esters is carried out in a neutral medium since, for example, if ethyl alcohol is treated with an aqueous solution of potassium nitrate no oxidation of the ethyl alcohol occurs even if the mixture of compounds is boiled. 

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. 

The amine function of a-amino acids and esters reacts with nitrous acid in a manner similar to that described for primary amines (Section 23-10A). The diazonium ion intermediate loses molecular nitrogen in the case of the acid, but the diazonium ester loses a proton and forms a relatively stable diazo compound known as ethyl diazoethanoate ... 

Exercise 25-13 Explain why glycine itself, as the dipolar ion, reacts with nitrous acid to eliminate nitrogen, whereas the ethyl ester of glycine forms ethyl diazoethanoate. 

By-product.—Ethyl Nitrite (Ethyl ester of nitrous acid). 

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