Ammonia, reaction with nitrous acid

Reactions with Nitrous Acid.—With nitrous acid (HO—NO) primary amines, due to the presence of two remaining ammonia hydrogen atoms, react with the oxygen of nitrous acid which is linked directly to the nitrogen alone. In the case of the alkyl amines the reaction does not stop here, but the hydroxyl group of the nitrous acid unites with the alkyl radical forming an alcohol and the nitrogen is set free. 

The plasma level of paracetamol can be determined by gas-liquid chromatography, by its UV absorption spectrum following extraction, and by its colorimetric reaction with nitrous acid to form a yellow coloured nitrophenol (the Glynn and Kendal method). Paracetamol can be detected in urine by a screening test which consists of its hydrolysis to /7-aminophenol, followed by its reaction with o-cresol and ammonia to form a blue in-dophenol. 

Dinitraminopropane (174) reacts with a range of primary amines in the presence of formaldehyde to yield l,5-dinitro-l,3,5-triazacyclooctanes like (187) (R = methyl), (188) (R = ethyl), and (189) (R = ixo-propyl). When ammonia is used as the amine component in these reactions the bicycle (192) is formed. Reaction of the bicycle (192) with nitrous acid and absolute nitric acid leads to C-N bond cleavage with the formation of (190) and (191), respectively. ... 

Parnell has reexamined the reaction of anthraniionitrile with ammonia, found that o-aminobenzamidine can in fact be prepared relatively easily, and shown that it is converted into 56, R = H, on diazotization." Reaction of 57 under the same conditions gives 58. Treatment of A,A -diaryl-o-aminobenzamidines (59) with nitrous acid... 

The 5-nitrosopyrrolopyrimidine (46) is converted by potassium pyrosulfate or triphenylphosphine into the pyrimidinopyrimidine (47). The reaction is thought to go via a nitrene, captured by intramolecular insertion. Nucleophilic attack by ammonia or primary amines at C-6 leads to the same ring enlargement, probably by the mechanism indicated. Treatment of the product (48 R = H)] with nitrous acid produces a compound (47) identical with that from the pyrosulfate reaction (Scheme 15) (72CPB2076). 

Tertiary Amines.—In the tertiary amines there is no remaining ammonia hydrogen therefore, neither the primary nor secondary amine reactions can take place. The fact is that tertiary amines do not react with nitrous acid at all. We thus have a reaction which enables us to distinguish between primary, secondary and tertiary amines. Writing these reactions together we have... 

The chelated metal ion does not seem to affect the pathway of the nitration reactions, but does have an effect on their course. The reaction of nickel(II) acetylacetonate with nitrous acid in water, ethanol, or ethanol-water solutions in the presence of ammonium acetate gave a red compound, N CsHjNsChK which was diamagnetic, monomeric in chloroform solution, and a nonelectrolyte in nitrobenzene. A similar compound was obtained with Pd(II), and the presence of ammonia was found to be essential for the formation of these two compounds. The corresponding compounds of Cu(II) and Pt(II) could not be prepared under the same experimental conditions. The infrared spectra of the nickel and palladium complexes are compatible with the two structures (XII) and (XIII), and on this evidence... 

When methylamine is treated with nitrous acid, a reaction takes place which is analogous to that between ammonia and the acid. In the cold a nitrite is formed, but when gently heated decomposition takes place and nitrogen is set free. The reactions in the case of ammonia and methylamine are represented by the equations,—... 

Good examples to start with are ammonia, the simplest amine, and its hydroxy derivative, hydroxylamine. Both react readily with nitrous acid in acidic aqueous solution, as shown in Schemes (3-1) and (3-2) ammonia yields molecular nitrogen. This method was used as a preparative process for N2 decades before fractionation of air became commercially available. The product of the corresponding reaction of hydroxylamine is dinitrogen oxide (originally called nitrous oxide). 

Curtius discovered HN3 [1] by reacting benzoylhydrazine with nitrous acid (b + g-type reaction). The resulting benzoyl azide was saponified, and sodium azide was isolated from the alkaline mixture. In 1903 Wislicenus [14] synthesized sodium azide solely from inorganic compounds, namely, sodium metal, ammonia, and dinitrogen oxide (a + e). The reaction proceeds in two steps, first converting ammonia with sodium to sodamide, and then reacting this with dinitrogen oxide to yield sodium azide. Fifty percent of the sodamide is decomposed to hydroxide and ammonia, and the overall balance of the process is... 

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