Sodium nitrite, reaction with

Thus, the reaction of alkyl halides and a-halo esters with sodium nitrite provides a very useful synthetic method for nitroalkanes and a-nitro esters. However, ethyl bromoacetate is exceptional in that it fails to give ethyl nitroacetate on treatment with sodium nitrite.93 This is due to the acidic hydrogen of the ethyl nitroacetate, which undergoes a further reaction with sodium nitrite to give the oxidized products (see Section 6.1, which discusses the Nef reaction). In a similar way, the reaction of benzyl bromide with sodium nitrite at 25 °C gives benzoic acid predominantly. To get phenylnitromethane, the reaction must be carried out at low temperature (-16 °C) (Eq. 2.48).93... 

Cyclization of 776 with ortho-esters gave (83JOC1628) [l,2,4]triazolo-[4,3-fc]pyrimido[5,4-< ][ 1,2,4]triazines 777, whereas reaction with sodium nitrite afforded the corresponding tetrazolopyrimidotriazine 778.3-Azido-pyrimido[4,5-e][l, 2,4]triazine 779 exists in a cyclic form as tetrazolo derivative 780, as shown by X-ray analysis (86KGS114). In solution the position of the 779 780 equilibrium depended on temperature and solvent. Higher temperatures favored 779. Azido compound 779 predominated in water, and tetrazolo compound 780 predominated in pyridine. Addition of sodium azide to the aqueous solution shifted the equilibrium toward 780. The... 

Azide 367 is prepared from 4-r -butyl-2-nitroaniline in 76% yield by its diazotization followed by treatment with sodium azide. In a 1,3-dipolar cycloaddition with cyanoacetamide, azide 367 is converted to triazole 368 that without separation is directly subjected to Dimroth rearrangement to give derivative 369 in 46% yield. Reduction of the nitro group provides ortfc-phenylenediamine 371 in 91% yield <2000EJM715>. Cyclocondensation of diamine 371 with phosgene furnishes benzimidazol-2-one 370 in 39% yield, whereas its reaction with sodium nitrite in 18% HC1 leads to benzotriazole derivative 372, which is isolated in 66% yield (Scheme 59). Products 370 and 372 exhibit potassium channel activating ability <2001FA841>. 

Malononitrile, purification of, 48, 3 reaction with sodium nitrite and acetic acid, 48,1... 

Nitration of the amine (139) with mixed acid yields the energetic nitramine (140). The same reaction with sodium nitrite in sulfuric acid, or with nitrosyl fluoride in methylene chloride, yields the nitrosamine (141), which is also an energetic high explosive. ... 

Hoshino H, Tanooka H Carcinogenicity of triethanolamine in mice and its mutagenicity after reaction with sodium nitrite in bacteria. Cancer Res 38 3918, 1978... 

Among other characteristic chemical reactions of the sugar nitrates, the reaction with sodium nitrite ethanol solution deserves attention. It is used to remove... 

B-4. Which of the following arylamines will not form a diazonium salt on reaction with sodium nitrite in hydrochloric acid ... 

The chemical properties of 1,4-dinitropyrazole [654] and l,4-dimethyl-3,5-dini-tropyrazole obtained by the nitration of 1,4-dimethylpyrazole [655], nitrotriazoles [656-663], and other nitroazoles [662, 664-666] have been studied. 1,4-Dinitro-pyrazole undergoes ring transformation reactions with primary amines, hydrazines, hydroxylamine, and amidines [654], Acid hydrolysis of dinitropyrazole leads to (l-methyl-3,5-dinitropyrazol-4-yl)acetaldehyde, and the reaction with sodium nitrite in hydrochloric acid furnishes 2-hydroxymino-2-(l-methyl-3,5-dinitropyra-zol-4-yl)acetaldehyde [655],... 

O2, ethanol + iodine + mercury oxide (at 35°C), CIO2, crotonaldehyde (above 180°C), buten-3-yne (with heat and pressure). Reaction with sodium nitrite forms a spontaneously flammable product. Exothermic reaction with boron trifluoride etherate + phenol. To fight fire, stop flow of gas. When heated to decomposition it emits acrid smoke and fumes. 

Reaction with Sodium Nitrite and Electrophilic Iodine Reagents... 

Bases, Neutral Salts.— As a base it forms salts, in which form the diazo compound is obtained by diazotization, and which though also unstable has been isolated in small quantities and the composition and properties determined. Of the three salts, the sulphate, chloride and nitrate, the first is the most stable and the last is the least stable. They are colorless crystalline neutral compounds soluble in water, difficultly soluble in alcohol and insoluble in ether. After being prepared by the ordinary diazo reaction, with sodium nitrite in cold acid water solution, they may be precipitated in crystalline form by the addition of alcohol and ether. If the diazotization is effected in alcohol solution by means of amyl nitrite or ethyl nitrite the crystals of the diazonium salt separate at once. These salts of diazo benzene all show true salt characteristics, e.g., they lower the freezing point of solutions. The diazo radical, (CeHs—N2—) is thus basic toward strong acids, and the hydroxide, the non-isolated hypothetical diazo benzene, CeHs—N2—OH, is the free base. It may be considered as the simplest aromatic diazo compound and the mother substance of all other members of the class. 

In the case of [RuCl(bpy)2(H20)]+ (bpy is 2,2 -bipyridine) no reaction with sodium nitrite is observed after an hour whereas in the presence of acid the following reaction occurs instantaneously (48) ... 

Acid or basic hydrolysis of 1,3-diacyl and 1,3-disulfonyl derivatives gives N-l derivatives.1,261 3-Acetyl-l,5,5-trimethylhydantoin exhibits a remarkable regioselectivity in acylation reactions of amines or phenols bearing alcoholic groups (Scheme 11).262 Nitrosation in an aqueous medium gives satisfactory yields in only a few examples.263 The reaction with sodium nitrite and me-thanesulfonic acid in dichloromethane affords 1-nitrosohydantoins.264 1,3-... 

Use of (-amyl chloroformate to give the /-amyloxycarbonylamino acids has some limitations since strictly anhydrous conditions are required. Sakakibara5 has converted the reagent into the more useful (-amyl azidoformate (b.p. 81.5—82°/51—53 mm.) by reaction with anhydrous hydrazine to give (-amyl carbazate followed by reaction with sodium nitrite (compare synthesis of (-butyl azidoformate [see 1, 84]). The azidoformate reacts with amino acids in aqueous dioxane in the presence of triethylamine to give (V-r-amyloxycarbonylamino acids in yields of 70-95%. 

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