Loss of nitrogen

The mechanism of the reaction may involve the formation of an anion by the base B, followed by the shift of hydrogen on the hydrazone anion with simultaneous loss of nitrogen to yield a carbanion ... 

Rearrangement of the diazo ketone, with loss of nitrogen, in the presence of suitable reagents and a catalyst (colloidal silver, silver oxide, or silver nitrate in the presence of ammonia solution). An acid is formed In the presence of water, an amide results when ammonia or an amine is used, and an ester is produced in the presence of an alcohol ... 

The mechanism of the reaction probably involves the production of bivalent carbon during the initial loss of nitrogen the group R shifte from an adjacent position to this carbon leading to the production of a keten the latter then reacts with the solvent to give an acid, an amide or an ester. 

Primary arylamines like primary alkylammes form diazonium ion salts on nitro sation Aryl diazonium 10ns are considerably more stable than their alkyl counterparts Whereas alkyl diazonium 10ns decompose under the conditions of their formation aryl diazonium salts are stable enough to be stored m aqueous solution at 0-5°C for a rea sonable time Loss of nitrogen from an aryl diazonium ion generates an unstable aryl cation and is much slower than loss of nitrogen from an alkyl diazonium ion... 

A reaction of aryl diazonium salts that does not involve loss of nitrogen takes place when they react with phenols and arylamines Aryl diazonium ions are relatively weak elec trophiles but have sufficient reactivity to attack strongly activated aromatic rings The reaction is known as azo coupling two aryl groups are joined together by an azo (—N=N—) function... 

The diazonium ion from 2 2 dimethylpropylamine rearranges via a methyl shift on loss of nitrogen to give 1 1 dimethylpropyl cation... 

More convenient is the use of aryl a2ides which are readily converted into isocyanates upon heating in nonreactive solvents via the loss of nitrogen. The latter method is useful for the synthesis of isocyanates with additional substituents which could not be prepared with phosgene (20). 

Loss of nitrogen occurs to give the cyclopropene (16), which loses a proton to yield the charged species Loss of HCN leads to the unsaturated... 

The only recorded synthesis of this type from a pyridazine involves the [4 + 2] cycloaddition of the lactim ether (374) with l,2,4,5-tetrazine-3,6-dicarboxylic ester, which proceeds with loss of nitrogen and methanol from the intermediate adduct to give the pyrido[2,3-t/]pyridazine (375) (77AP936). 

To minimize the loss of nitrogen in the form of ammonia gas, pH should not rise above about 8.5. 

Figure 3 Partitioning of losses of nitrogen fertilizer between denitrifieation and leaehing in 13 experiments. (Taken from Addiseott and Powlson, with permission of Cambridge University Press.)...

Figure 4 Losses of nitrogen as nitrate during 38 years from soil that was uneropped, uneultivated, and unfertilized. (Taken from Addiseott et air)...

Figure 6 Losses of nitrogen as nitrate from grazed grassland related to the amount of fertilizer applied. The solid and broken lines refer to undrained and drained land, respeetively. (Taken from Seholefield et...

The interest in gaseous losses of nitrogen from soil is now extensive and includes the well established community of soil scientists concerned with losses of fertilizer-applied nitrogen by nitrification and denitrification. More recently, interest in ammonia losses from plants and soil has been stimulated by the very large emissions from intensive cattle production in the Netherlands and their... 

K. A. Smith and J. R. M. Arah, Losses of Nitrogen by Denitrification and Emissions of Nitrogen Oxides from Soils, The Fertiliser Soeiety, 1990, Proeeedings No. 299. 

The gaseous losses of nitrogen from agriculture include a range of oxidized (NO and NjO) as well as reduced (NHj) compounds. These gases form a part of the... 

One of the best leaving groups is molecular nitrogen in alkyl diazonium ions. Diazonium ions are generated by nitrosation of primaiy amines. The diazonium ions generated from alkyl amines are veiy unstable and immediately decompose with loss of nitrogen. 

There are several methods for generation of benzyne in addition to base-catalyzed elimination of hydrogen halide from a halobenzene, and some of these are more generally applicable for preparative work. Probably the most convenient method is diazotization of o-aminobenzoic acid. Concerted loss of nitrogen and carbon dioxide follows diazotization and generates benzyne. Benzyne can be formed in this manner in the presence of a variety of compounds with which it reacts rapidly. 

Lai ge tanks (say. over 1,000 m ) blanketed with nitrogen should be fitted with low-pressure alarms to give immediate warning of the loss of nitrogen blanketing. 

Perfluoroisobutylene undergoes cycloadditions with azides only at elevated temperatures, the reaction can lead to subsequent loss of nitrogen [6] (equation 4) In another high-temperature reaction, chlorotrifluoroethylene undergoes cy cloaddition with the azomethineylide generated from the thermal electrocyclic nng opening of an azindine, a reaction that contributes to a good overall synthesis of 3,4-difluoropyrroles [7] (equation 5)... 

The Boger pyridine synthesis involves the reaction of triazine 1 with activated alkene 2 in a hetero-Diels-Alder fashion. The intermediate bicyclic species 3 is unstable and a facile cycloreversion takes place due to the loss of nitrogen gas to afford the appropriately substituted pyridine derivative 4. 

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